Separation, storage, and catalytic conversion of fluids using ITQ-55

ABSTRACT

This invention refers to a microporous crystalline material of zeolitic nature that has, in its calcined state and in the absence of defects in its crystalline matrix manifested by the presence of silanols, the empirical formula
 
 x (M 1/n XO 2 ): y YO 2   :g GeO 2 :(1− g )SiO2
         in which   M is selected between H + , at least one inorganic cation of charge +n, and a mixture of both,   X is at least one chemical element of oxidation state +3,   Y is at least one chemical element with oxidation state +4 different from Si,   x takes a value between 0 and 0.2, both included,   y takes a value between 0 and 0.1, both included,   g takes a value between 0 and 0.5, both included
 
that has been denoted ITQ-55, as well as a method for its preparation. This invention also relates to uses of the crystalline material of zeolitic nature for adsorption of fluid components, membrane separation of fluid components, storage of fluid components, and catalysis of various conversion reactions.

CLAIM OF FOREIGN PRIORITY

Pursuant to 35 U.S.C. 119(a), this application claims the benefit ofApplication No. P201430935 filed in Spain, reception office OEPM Madrid,on Jun. 20, 2014.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is related to four other co-pending U.S. applications,filed on Jun. 19, 2015 as follows: Ser. No. 14/744,169; Ser. No.14/744,485; Ser. No. 14/744,334; and Ser. No. 14/744,248. Each of theseco-pending U.S. applications are hereby incorporated by reference hereinin their entirety.

FIELD OF THE INVENTION

This invention belongs to the technical field of microporous crystallinematerials of zeolitic nature, useful as adsorbents, catalysts orcatalytic components, for transformation processes and in particular forthe adsorption and separation of organic and inorganic compound in gasor liquid phase.

BACKGROUND OF THE INVENTION

Zeolites are a microporous crystalline material formed by a matrix ofTO4 tetrahedrons that share all their vertices giving rise to athree-dimensional structure that contains channels and/or cavities ofmolecular dimensions. They are of variable composition, and T generallyrepresents atoms with formal oxidation state +3 or +4, such as forexample Si, Ge, Ti, Al, B, or Ga. When some of the T atoms have anoxidation state less than +4, the crystalline matrix formed presentsnegative charges that are compensated by means of the presence in thechannels or cavities of organic or inorganic cations. These channels andcavities may also contain organic molecules and H₂O, therefore, in ageneral manner, the chemical composition of the zeolites may berepresented by means of the following empirical formula:x(M_(1/n)XO₂):yYO₂ :zR:wH₂O

where M is one or several organic or inorganic cations of charge +n; Xis one or several trivalent elements; Y is one or several tetravalentelements, generally Si; and R is one or several organic substances.Although by means of postsynthesis treatments the nature of M, X, Y andR and the values of x, y, z, and w may vary, the chemical composition ofa zeolite (just as is synthesized or after its calcining) possesses acharacteristic range for each zeolite and its method of preparation.

The crystalline structure of each zeolite, with a system of channels andspecific cavities, gives rise to a characteristic diffraction pattern ofX-rays, which allows one to differentiate them from each other.

Many zeolites have been synthesized in presence of an organic moleculethat acts as a structure director agent. The organic molecules that actas structure director agents (SDA) generally contain nitrogen in theircomposition, and they can give rise to stable organic cations in thereaction medium.

The mobilization of the precursor species during the zeolites synthesismay be carried out in the presence of hydroxyl groups and basic mediumthat can be introduced as hydroxide of the same SDA, such as for exampletetrapropylammonium hydroxide in the case of the zeolite ZSM-5. Thefluoride ions can also act as mobilizing agents in synthesis ofzeolites, for example in the patent EP-TO-337479 the use of HF isdescribed in H₂O at low pH as a mobilizing agent of silica for thezeolite ZSM-5 synthesis.

SUMMARY OF THE INVENTION

This invention refers to a new microporous crystalline material ofzeolitic nature, identified as “zeolite ITQ-55,” its preparation methodand its use.

ITQ-55 (INSTITUTO DE TECNOLOGÍA QUÍMICA number 55) is a new crystallinemicroporous material having a framework of tetrahedral atoms connectedby bridging atoms, the tetrahedral atom framework being defined by theinterconnections between the tetrahedrally coordinated atoms in itsframework. ITQ-55 is stable to calcination in air, absorbs hydrocarbons,and is catalytically active for hydrocarbon conversion.

This material, both in its calcined form and synthesized withoutcalcining has an X-ray diffraction pattern that is different from otherwell-known zeolitic material and, therefore, is characteristic of thismaterial.

In various aspects, the material is suitable for use in separationsbased on selective adsorption of fluid components. In various aspects,the material is suitable for use in membrane separations of fluidcomponents. In various aspects, the material is suitable for use forstorage of a fluid component. In various aspects, the material issuitable for use in catalyzing conversion reactions of organic compoundsand/or syngas.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 represents the X-ray diffraction pattern of the mostcharacteristic peaks of the purely siliceous ITQ-55 material, as issynthesized, obtained according to Example 2.

FIG. 2 represents the X-ray diffraction pattern of the mostcharacteristic peaks of the material of the example 2 in calcined state.

FIG. 3 represents the X-ray diffraction pattern of the mostcharacteristic peaks of the ITQ-55 material that contains Al and Si inits composition, as is synthesized, obtained according to example 4.

FIG. 4 represents the adsorption selectivity of CO₂ over that of methanein the ITQ-55 material in its calcined form, obtained according toexample 2. The selectivity is expressed as the ratio of the adsorptioncapacity obtained starting from the isotherms of the pure gases.

FIG. 5 represents the framework structure of ITQ-55 showing only thetetrahedral atoms.

FIG. 6 hereof is a representation of one embodiment of a parallelchannel contactor in the form of a monolith directly formed from amicroporous adsorbent and containing a plurality of parallel channels.

FIG. 7 hereof is a cross-sectional representation along the longitudinalaxis of the monolith of FIG. 6.

FIG. 8 hereof is a representation of a magnified section of thecross-sectional view of the monolith of FIG. 7 showing the detailedstructure of the adsorbent layer along with a blocking agent occupyingsome of the mesopores and macropores.

FIG. 9 hereof is another representation of an embodiment of a parallelchannel contactor in the form of a coated monolith where the adsorbentlayer is coated onto the channel wall.

FIG. 10 hereof is a representation of an embodiment of a parallelcontactor that is constructed from parallel laminate sheets.

FIG. 11 shows the size of the unit cell for ITQ-55 determined bymeasured values and determined by simulation.

FIG. 12 shows additional results from molecular dynamics simulationsrelated to the minimum aperture (or pore) size in the unit cell forITQ-55.

FIG. 13 shows adsorption isotherms at 28° C. for ITQ-55 crystals at lowpressures.

FIG. 14 shows adsorption isotherms for CO₂ and N₂ for an expanded rangeof pressures at 30° C.

FIG. 15 shows isosteric heats of adsorption for CO₂ and N₂.

FIG. 16 shows the equilibrium loading of N₂ in mol per kg of ITQ-55 at5° C. and 25° C.

FIG. 17 shows the equilibrium loading of H₂O for ITQ-55 in comparisonwith zeolite 5A.

FIG. 18 shows adsorption isotherms at 28° C. for C₂H₄, Ar, Kr, and CH₄.

FIG. 19 shows a comparison of equilibrium adsorption of methane andethylene at 1 bara (101 kPa) and 28° C.

FIG. 20 shows adsorption isotherms for H₂ at up to 10 bar (about 1 MPaa)at −10° C. and CH₄ at 28° C.

FIG. 21 shows adsorption as a function of the square root of time at 1bar (101 kPa) and 30° C. for CO₂, N₂, CH₄, and C₂H₄.

FIG. 22 shows additional data related to uptake as a function of timefor N₂, CO₂, CH₄, C₂H₆, and C₂H₄.

FIGS. 23A and 23B show scanning electron microscopy (SEM) images ofITQ-55 crystals.

FIGS. 24 and 25 show kinetic studies with frequency response for CH₄ andCO₂ (FIG. 24) and N₂ (FIG. 25) on an ITQ-55 sample.

FIG. 26 shows the temperature dependence of diffusion time constants forethane and ethylene.

FIG. 27 shows ZLC results for CO₂ in ITQ-55.

FIG. 28 shows calculated adsorption isotherms for acetylene on ITQ-55.

DETAILED DESCRIPTION OF THE EMBODIMENTS

This invention refers in the first place to a microporous crystallinematerial of zeolitic nature that has, in calcined state and in absenceof defects in its crystalline matrix manifested by the presence ofsilanols, the empirical formulax(M_(1/n)XO₂):yYO₂ :gGeO₂:(1−g)SiO₂

in which,

M is selected among H+, at least one inorganic cation of charge +n, anda mixture of both, preferably selected among H+, at least one inorganiccation of charge +n selected among alkaline, alkaline-earth metals andcombinations thereof, and a mixture of both,

X is at least one chemical element of oxidation state +3, selectedpreferably between Al, Ga, B, Fe, Cr and mixtures of the same.

Y is at least one chemical element with oxidation state +4 differentfrom Si, selected preferably between Ti, Sn, Zr, V and mixtures of thesame.

x takes a value between 0 and 0.2, both included, preferably less than0.1.

y takes a value between 0 and 0.1, both included, preferably less than0.05.

g takes a value between 0 and 0.5, both included, preferably less than0.33.

and because the material, as it is synthesized, has an X-ray diffractionpattern with, at least, the angle values 2θ (degrees) and relativeintensities (I/I₀) shown in the Table I, I₀ being the intensity of thehighest peak to which is assigned a value of 100:

TABLE I 2θ (degrees) ± 0.5 Intensity (I/I₀) 5.8 w 7.7 w 8.9 w 9.3 mf 9.9w 10.1 w 13.2 m 13.4 w 14.7 w 15.1 m 15.4 w 15.5 w 17.4 m 17.7 m 19.9 m20.6 m 21.2 f 21.6 f 22.0 f 23.1 mf 24.4 m 27.0 m

where w is a relative weak intensity between 0 and 20%,

m is an relative medium intensity between 20 and 40%,

f is a relative strong intensity between 40 and 60%, and

mf is a very strong relative intensity between 60 and 100%.

The microporous crystalline material of zeolitic nature according to theinvention, after being calcined to eliminate the organic compoundsoccluded in its interior, possesses an X-ray diffraction pattern with,at least, the angle values 2θ (degrees) and relative intensities (I/I₀)indicated in the Table II:

TABLE II 2θ (degrees) ± 0.5 Intensity (I/I₀) 6.2 w 7.8 w 8.0 w 9.8 mf10.0 m 10.3 w 12.3 w 13.4 w 13.7 w 15.0 w 15.2 w 16.8 w 18.1 w 20.1 w21.3 w 23.5 w 23.9 w 26.8 w

where w, m, f and mf have the previous meaning

According to a preferred embodiment of this invention the microporouscrystalline material of zeoltic nature ITQ-55, has, in calcined stateand in absence of defects in its crystalline matrix manifested by thepresence of silanols, the empirical formulax(M_(1/n)XO₂):yYO₂ :gGeO₂:(1−g)SiO₂

in which

M is selected among H⁺, at least one inorganic cation of charge +n,preferably alkaline or alkaline earth, alkaline, alkaline-earth metalsand combinations of the same,

X is at least one chemical element of oxidation state +3, selectedbetween Al, Ga, B, Fe, Cr and mixtures of the same,

Y is at least one chemical element with oxidation state +4 differentfrom Si, selected among Ti, Sn, V, Zr and mixtures of the same,

x takes a value between 0 and 0.1, both included,

y takes a value between 0 and 0.05, both included,

g takes a value between 0 and 0.33, both included,

and the material, as is synthesized, has an X-ray diffraction patternwith at least, the angle values 2θ (degrees) and relative intensitiesmentioned previously (Table I) and this material in calcined state hasan X-ray diffraction pattern with, at least, the angle values 2θ(degrees) and relative intensities (I/I₀) mentioned previously (TableII).

According to a preferred embodiment of this invention the microporouscrystalline material of zeolitic nature ITQ-55 is a pure silicamaterial, that is to say that in the general formula indicatedpreviously “x”, “y” and “g” they take the value 0.

According to another preferred embodiment of this invention themicroporous crystalline material of zeolitic nature ITQ-55 is a materialthat can have in the general formula previously indicated “x” equal to0, “y” equal to 0 and “g” different from 0.

According to another preferred embodiment of this invention themicroporous crystalline material of zeolitic nature ITQ-55 is a materialin whose general formula:

X is selected between Al, Ga, B, Fe, Cr, and combinations of the same,

y takes the value 0, and

g takes the value 0.

Another preferred embodiment of this invention the microporouscrystalline material of zeolitic nature ITQ-55 is a material, which canhave in its general formula:

Y is selected between Ti, Zr, Sn, and combinations of the same,

x takes the value 0, and

g takes the value 0.

According to another preferred embodiment the microporous crystallinematerial of zeolitic nature ITQ-55 is a material in whose generalformula:

X is Al, Ga, B, Fe, Cr, and combinations of the same,

Y is Ti, Zr, Sn, and combinations of the same and

g take the value 0.

In one particular embodiment, the microporous crystalline material ofzeolitic nature ITQ-55 is a material in whose general formula:

X is Al, Ga, B, Fe, Cr, and combinations of the same,

y takes the value 0, and

g takes a value different from 0 and less than 0.33.

Another particular embodiment describes the microporous crystallinematerial of zeolitic nature ITQ-55 in whose general formula:

Y is Ti, Zr, Sn, and combinations of the same,

x takes the value 0, and

g takes a value different from 0 and less than 0.33.

In another particular embodiment, the microporous crystalline materialof zeolitic nature ITQ-55 is a material in whose general formula:

X is Al, Ga, B, Fe, Cr, and combinations of the same,

Y is Ti, Zr or Sn, and

g takes a value different from 0 and less than 0.33.

The X-ray diffraction patterns of the ITQ-55 material has been obtainedby the powder method using a fixed divergence slit of ⅛° and using theKα radiation of Cu. It should be kept in mind that the diffraction datalisted for this zeolite sample ITQ-55 as single or unique lines, can beformed from multiple overlapping reflections that, under certainconditions, such as differences in crystallographic changes, may appearas resolved or partially resolved lines. Generally, the crystallographicchanges may include small variations in the parameters of the unit celland/or changes in the symmetry of the unit cell, without a change takingplace in the structure. Thus, the positions, widths and relativeintensities of the peaks depend in a certain measure on the chemicalcomposition of the material, as well as of the degree of hydration andthe crystal size.

In particular, when the matrix is composed exclusively by silicon oxideand has been synthesized in the presence of fluoride anions using thequaternary cation diammoniumN²,N²,N²,N⁵,N⁵,N⁵,3a,6a-octamethylo-octahydropentalene-2,5-diammonium asstructure director agent, the ITQ-55 zeolite as synthesized presents anX-ray diffraction pattern like the one that is shown in FIG. 1. Thisdiagram is characterized by the angle values 2θ (degrees) and relativeintensities (I/I₀) that are presented in Table III, where w, m, f and mfhave the same meaning as in the Table I.

TABLE III 2θ (degrees) ± 0.5 Intensity (I/I₀) 5.78 w 7.68 w 8.91 w 9.31mf 9.93 w 10.14 w 13.23 m 13.42 w 14.70 w 15.06 m 15.40 w 15.52 w 16.55w 16.84 w 17.05 w 17.40 m 17.73 m 18.02 w 18.60 w 19.93 m 20.56 m 21.17f 21.47 m 21.56 f 22.01 f 22.51 w 22.88 w 23.14 mf 24.05 w 24.42 m 24.62w 25.28 w 25.49 w 26.61 w 26.95 m 27.95 w 28.24 w 28.59 w 28.93 w 29.21w 29.68 w

The X-ray diffraction pattern of the previous sample of ITQ-55 afterbeing calcined at 800° C. to eliminate the organic compounds occluded inits interior is shown in the FIG. 2. This diffractogram is characterizedby the angle values 2θ (degrees) and relative intensities (I/I₀) thatare shown in the Table IV, where w, m, f and mf have the same meaningsas in Table I. The comparison of the diffractograms of X-rayscorresponding to zeolite ITQ-55 as is synthesized and in calcined stateshow that the material is thermally stable.

TABLE IV 2θ (degrees) Intensity (I/I₀) 6.18 w 7.80 w 7.98 w 9.82 mf10.02 m 10.29 w 12.31 w 13.35 w 13.68 w 14.98 w 15.22 w 15.52 w 16.82 w18.09 w 18.43 w 20.06 w 20.81 w 21.34 w 21.67 w 23.45 w 23.92 w 24.39 w24.99 w 26.80 w 27.48 w 27.91 w 28.43 w 29.61 w

As with any porous crystalline material, the structure of ITQ-55 can bedefined not only by its X-ray diffraction pattern but by its frameworkstructure, i.e., the interconnections between the tetrahedrallycoordinated atoms in its framework. In particular, ITQ-55 has aframework of tetrahedral (T) atoms connected by bridging atoms, whereinthe tetrahedral atom framework is defined by connecting the nearesttetrahedral (T) atoms in the manner given in Table V.

TABLE V ITQ-55 tetrahedral atom interconnections T atom Connected to: T1T6, T7, T55, T73 T2 T3, T5, T9, T56 T3 T2, T7, T21, T27 T4 T8, T9, T58,T73 T5 T2, T8, T52, T59 T6 T1, T8, T53, T60 T7 T1, T3, T50, T61 T8 T4,T5, T6, T51 T9 T2, T4, T21, T63 T10 T15, T16, T64, T74 T11 T12, T14,T18, T65 T12 T11, T16, T30, T36 T13 T17, T18, T67, T74 T14 T11, T17,T43, T68 T15 T10, T17, T44, T69 T16 T10, T12, T41, T70 T17 T13, T14,T15, T42 T18 T11, T13, T30, T72 T19 T24, T25, T37, T73 T20 T21, T23,T27, T38 T21 T3, T9, T20, T25 T22 T26, T27, T40, T73 T23 T20, T26, T41,T70 T24 T19, T26, T42, T71 T25 T19, T21, T43, T68 T26 T22, T23, T24, T69T27 T3, T20, T22, T45 T28 T33, T34, T46, T74 T29 T30, T32, T36, T47 T30T12, T18, T29, T34 T31 T35, T36, T49, T74 T32 T29, T35, T50, T61 T33T28, T35, T51, T62 T34 T28, T30, T52, T59 T35 T31, T32, T33, T60 T36T12, T29, T31, T54 T37 T19, T42, T43, T75 T38 T20, T39, T41, T45 T39T38, T43, T57, T63 T40 T22, T44, T45, T75 T41 T16, T23, T38, T44 T42T17, T24, T37, T44 T43 T14, T25, T37, T39 T44 T15, T40, T41, T42 T45T27, T38, T40, T57 T46 T28, T51, T52, T76 T47 T29, T48, T50, T54 T48T47, T52, T66, T72 T49 T31, T53, T54, T76 T50 T7, T32, T47, T53 T51 T8,T33, T46, T53 T52 T5, T34, T46, T48 T53 T6, T49, T50, T51 T54 T36, T47,T49, T66 T55 T1, T60, T61, T75 T56 T2, T57, T59, T63 T57 T39, T45, T56,T61 T58 T4, T62, T63, T75 T59 T5, T34, T56, T62 T60 T6, T35, T55, T62T61 T7, T32, T55, T57 T62 T33, T58, T59, T60 T63 T9, T39, T56, T58 T64T10, T69, T70, T76 T65 T11, T66, T68, T72 T66 T48, T54, T65, T70 T67T13, T71, T72, T76 T68 T14, T25, T65, T71 T69 T15, T26, T64, T71 T70T16, T23, T64, T66 T71 T24, T67, T68, T69 T72 T18, T48, T65, T67 T73 T1,T4, T19, T22 T74 T10, T13, T28, T31 T75 T37, T40, T55, T58 T76 T46, T49,T64, T67

Tetrahedral atoms are those capable of having tetrahedral coordination,including one or more of, but not limiting, lithium, beryllium, boron,magnesium, aluminum, silicon, phosphorous, titanium, chromium,manganese, iron, cobalt, nickel, copper, zinc, zirconium, gallium,germanium, arsenic, indium, tin, and antimony.

The synthetic porous crystalline material of this invention, ITQ-55, isa crystalline phase which has a unique 1-dimensional channel systemcomprising 8-member rings of tetrahedrally coordinated atoms.

In addition, to describing the structure of ITQ-55 by theinterconnections of the tetrahedral atoms as in Table V above, it may bedefined by its unit cell, which is the smallest repeating unitcontaining all the structural elements of the material. The porestructure of ITQ-55 is illustrated in FIG. 5 (which shows only thetetrahedral atoms) down the direction of the straight 10-membered ringchannels. There is a single unit cell unit in FIG. 5, whose limits aredefined by the box. Table VI lists the typical positions of eachtetrahedral atom in the unit cell in units of Angstroms. Eachtetrahedral atom is bonded to bridging atoms, which are also bonded toadjacent tetrahedral atoms. Tetrahedral atoms are those capable ofhaving tetrahedral coordination, including one or more of, but notlimiting, lithium, beryllium, boron, magnesium, aluminum, silicon,phosphorous, titanium, chromium, manganese, iron, cobalt, nickel,copper, zinc, zirconium, gallium, germanium, arsenic, indium, tin, andantimony. Bridging atoms are those capable of connecting two tetrahedralatoms, examples which include, but not limiting, oxygen, nitrogen,fluorine, sulfur, selenium, and carbon atoms.

TABLE VI Positions of tetrahedral (T) atoms for the ITQ-55 structure.Values, in units of Ångströms, are approximate and are typical when T =silicon and the bridging atoms are oxygen. Atoms x(Å) y(Å) z(Å) T0112.759 8.224 8.934 T02 14.059 11.794 0.998 T03 11.771 10.088 13.568 T0412.623 11.812 5.674 T05 16.530 11.780 2.714 T06 15.245 8.218 7.129 T0713.401 8.226 11.857 T08 15.507 10.720 5.364 T09 11.679 11.813 2.804 T101.566 1.554 8.934 T11 2.866 5.124 0.998 T12 0.577 3.418 13.568 T13 1.4305.141 5.674 T14 5.337 5.109 2.714 T15 4.051 1.548 7.129 T16 2.208 1.55611.857 T17 4.314 4.050 5.364 T18 0.486 5.143 2.804 T19 8.980 8.224 5.550T20 7.680 11.794 13.487 T21 9.968 10.088 0.917 T22 9.116 11.812 8.811T23 5.209 11.780 11.770 T24 6.495 8.218 7.355 T25 8.338 8.226 2.627 T266.232 10.720 9.121 T27 10.060 11.813 11.680 T28 20.173 1.554 5.550 T2918.873 5.124 13.487 T30 21.162 3.418 0.917 T31 20.309 5.141 8.811 T3216.403 5.109 11.770 T33 17.688 1.548 7.355 T34 19.532 1.556 2.627 T3517.426 4.050 9.121 T36 21.253 5.143 11.680 T37 8.980 5.116 5.550 T387.680 1.546 13.487 T39 9.968 3.252 0.917 T40 9.116 1.529 8.811 T41 5.2091.561 11.770 T42 6.495 5.123 7.355 T43 8.338 5.115 2.627 T44 6.232 2.6209.121 T45 10.060 1.527 11.680 T46 20.173 11.786 5.550 T47 18.873 8.21613.487 T48 21.162 9.923 0.917 T49 20.309 8.199 8.811 T50 16.403 8.23111.770 T51 17.688 11.793 7.355 T52 19.532 11.785 2.627 T53 17.426 9.2909.121 T54 21.253 8.198 11.680 T55 12.759 5.116 8.934 T56 14.059 1.5460.998 T57 11.771 3.252 13.568 T58 12.623 1.529 5.674 T59 16.530 1.5612.714 T60 15.245 5.123 7.129 T61 13.401 5.115 11.857 T62 15.507 2.6205.364 T63 11.679 1.527 2.804 T64 1.566 11.786 8.934 T65 2.866 8.2160.998 T66 0.577 9.923 13.568 T67 1.430 8.199 5.674 T68 5.337 8.231 2.714T69 4.051 11.793 7.129 T70 2.208 11.785 11.857 T71 4.314 9.290 5.364 T720.486 8.198 2.804 T73 10.870 9.915 7.242 T74 22.063 3.244 7.242 T7510.870 3.426 7.242 T76 22.063 10.096 7.242

In the case of oxygen, it is also possible that the bridging oxygen isalso connected to a hydrogen atom to form a hydroxyl group (—OH—). Inthe case of carbon, it is also possible that the carbon is alsoconnected to two hydrogen atoms to form a methylene group (—CH₂—). Forexample, bridging methylene groups are present in the zirconiumdiphosphonate, MIL-57. See: C. Serre, G. Férey, J. Mater. Chem. 12, p.2367 (2002). In the case of nitrogen, it is also possible that thenitrogen bridging atom is part of an imidazolate anion. For example,bridging imidazolate groups are present in the zinc(II) imidazolatezeolite-type compounds, Zn(mim)₂.2H₂O, Zn(eim)₂.H₂O, andZn(eim/mim)₂.1.25H₂O. See: X-C. Huang, Y-Y. Lin, J-P. Zhang, X-M. Chen,Angew. Chem. Int. Ed. 45, p. 1557-1559 (2006). Bridging sulfur andselenium atoms have been seen in the UCR-20-23 family of microporousmaterials. See: N. Zheng, X. Bu, B. Wang, P. Feng, Science 298, p. 2366(2002). Bridging fluorine atoms have been seen in lithium hydraziniumfluoroberyllate, which has the ABW structure type. See: M. R. Anderson,I. D. Brown, S. Vilminot, Acta Cryst. B29, p. 2626 (1973). Sincetetrahedral atoms may move about due to other crystal forces (presenceof inorganic or organic species, for example), or by the choice oftetrahedral and bridging atoms, a range of ±1.0 Ångstrom is implied forthe x and coordinate positions and a range of ±0.5 Ångstrom for the yand z coordinate positions.

The complete structure of ITQ-55 is built by connecting multiple unitcells as defined above in a fully-connected three-dimensional framework.The tetrahedral atoms in one unit cell are connected to certaintetrahedral atoms in all of its adjacent unit cells. While Table V liststhe connections of all the tetrahedral atoms for a given unit cell ofITQ-55, the connections may not be to the particular atom in the sameunit cell but to an adjacent unit cell. All of the connections listed inTable V are such that they are to the closest tetrahedral (T) atoms,regardless of whether they are in the same unit cell or in adjacent unitcells.

Although the Cartesian coordinates given in Table VI may accuratelyreflect the positions of tetrahedral atoms in an idealized structure,the true structure can be more accurately described by the connectivitybetween the framework atoms as shown in Table V above.

Another way to describe this connectivity is by the use of coordinationsequences as applied to microporous frameworks by W. M. Meier and H. J.Moeck, in the Journal of Solid State Chemistry 27, p. 349 (1979). In amicroporous framework, each tetrahedral atom, N₀, (T-atom) is connectedto N₁=4 neighboring T-atoms through bridging atoms (typically oxygen).These neighboring T-atoms are then connected to N₂ T-atoms in the nextshell. The N₂ atoms in the second shell are connected to N₃ T-atoms inthe third shell, and so on. Each T-atom is only counted once, such that,for example, if a T-atom is in a 4-membered ring, at the fourth shellthe N₀ atom is not counted second time, and so on. Using thismethodology, a coordination sequence can be determined for each uniqueT-atom of a 4-connected net of T-atoms. The following line lists themaximum number of T-atoms for each shell.

N₀=1 N₁≦4 N₂≦12 N₃≦36 N_(k)≦4·3^(k-1)

TABLE VII Coordination sequence for ITQ-55 structure Atom coordinationsequence T1 4 10 20 36 54 73 100 135 181 224 T2 4 9 17 30 53 81 102 123161 209 T3 4 10 20 34 52 76 104 133 165 203 T4 4 11 21 32 49 76 108 141173 210 T5 4 12 22 34 46 74 108 144 174 212 T6 4 10 18 32 56 82 103 128170 217 T7 4 10 20 34 54 81 106 134 176 222 T8 4 10 21 36 54 74 98 131172 217 T9 4 11 19 33 57 79 103 136 172 217 T10 4 9 17 31 51 75 104 133165 206

One way to determine the coordination sequence for a given structure isfrom the atomic coordinates of the framework atoms using the computerprogram zeoTsites (see G. Sastre, J. D. Gale, Microporous and MesoporousMaterials 43, p. 27 (2001).

The coordination sequence for the ITQ-55 structure is given in TableVII. The T-atom connectivity as listed in Table V and is for T-atomsonly. Bridging atoms, such as oxygen usually connects the T-atoms.Although most of the T-atoms are connected to other T-atoms throughbridging atoms, it is recognized that in a particular crystal of amaterial having a framework structure, it is possible that a number ofT-atoms may not connected to one another. Reasons for non-connectivityinclude, but are not limited by T-atoms located at the edges of thecrystals and by defects sites caused by, for example, vacancies in thecrystal. The framework listed in Table V and Table VII is not limited inany way by its composition, unit cell dimensions or space groupsymmetry.

While the idealized structure contains only 4-coordinate T-atoms, it ispossible under certain conditions that some of the framework atoms maybe 5- or 6-coordinate. This may occur, for example, under conditions ofhydration when the composition of the material contains mainlyphosphorous and aluminum T-atoms. When this occurs it is found thatT-atoms may be also coordinated to one or two oxygen atoms of watermolecules (—OH₂), or of hydroxyl groups (—OH). For example, themolecular sieve AlPO₄-34 is known to reversibly change the coordinationof some aluminum T-atoms from 4-coordinate to 5- and 6-coordinate uponhydration as described by A. Tuel et al. in J. Phys. Chem. B 104, p.5697 (2000). It is also possible that some framework T-atoms can becoordinated to fluoride atoms (—F) when materials are prepared in thepresence of fluorine to make materials with 5-coordinate T-atoms asdescribed by H. Koller in J. Am. Chem Soc. 121, p. 3368 (1999).

In second place this invention refers to a method to synthesize themicroporous crystalline material ITQ-55.

According to this invention, the method to synthesize the microporouscrystalline material, ITQ-55, may include a reaction mixture thatincludes at least: one or several sources of SiO₂, one or severalsources of organic cation R, at least one source of anions selectedamong hydroxide anions, fluoride anions and combinations of the same andwater, it undergoes heating at a temperature between 80 and 200° C., andbecause the reaction mixture has a composition, in terms of molarratios, between the intervals

R⁺/SiO₂=0.01-1.0,

OH⁻/SiO₂=0-3.0

F⁻/SiO₂=0-3.0

(F⁻+OH⁻)/SiO₂=0.01-3.0,

H₂O/SiO₂=1-50.

According to an additional particular embodiment of the method thereaction mixture may include, also, one or more source of GeO₂ andbecause it has a composition, in terms of molar ratios, included betweenthe intervals

GeO₂/SiO₂=0 and 0.5

R⁺/(SiO₂+GeO₂)=0.01-1.0,

F⁻/(SiO₂+GeO₂)=0.0-3.0,

OH⁻/(SiO₂+GeO₂)=0.0-3.0,

(F⁻+OH⁻)/(SiO₂+GeO₂)=0.01-3.0

H₂O/(SiO₂+GeO₂)=1-50.

According to one additional particular embodiment of the method, theanion is preferably fluoride and the reaction mixture has a composition,in terms of molar ratios, between the intervals

GeO₂/SiO₂=0 and 0.5

R⁺/(SiO₂+GeO₂)=0.01-1.0,

F⁻/(SiO₂+GeO₂)=0.01-3.0,

H₂O/(SiO₂+GeO₂)=1-50.

According to another additional particular embodiment of the method, theanion is preferably hydroxide and may have a reaction mixture that has acomposition, in terms of molar ratios, between the intervals

GeO₂/SiO₂=0 and 0.5

R⁺/(SiO₂+GeO₂)=0.01-1.0,

OH⁻/(SiO₂+GeO₂)=0.01-3.0,

H₂O/(SiO₂+GeO₂)=1-50.

According to one additional particular embodiment of the method, thereaction mixture can include, also, at least, one source of one or moretrivalent elements X.

In one particular embodiment, the reaction mixture comprisesexclusively: one or several sources of SiO₂, at least one source of oneor several trivalent elements X, one or several sources of organiccation R, at least one source of anions selected among hydroxide anions,fluoride anions and the combinations of the same, and water, and it hasa composition, in terms of molar ratios, between the intervals

R⁺/SiO₂=0.01-1.0,

X₂O₃/SiO₂=0-0.1, excluding the value 0.

OH⁻/SiO₂=0-3.0

F⁻/SiO₂=0-3.0

(OH⁻+F⁻)/SiO₂=0.0-3.0, excluding the value 0, and

H₂O/SiO₂=1-50.

According to this embodiment, if you add to the reaction mixture, atleast one source of GeO₂, the composition, in terms of molar ratios willbe between the intervals

GeO₂/SiO₂=0 and 0.5, excluding the value 0

R⁺/(SiO₂+GeO₂)=0.01-1.0,

X₂O₃/(SiO₂+GeO₂)=0-0.1, excluding the value 0,

OH⁻/(SiO₂+GeO₂)=0-3.0

F⁻/(SiO₂+GeO₂)=0-3.0

(OH⁻+F⁻)/(SiO₂+GeO₂)=0.0-3.0, excluding the value 0, and

H₂O/(SiO₂+GeO₂)=1-50.

According to another particular embodiment the reaction mixturecomprises exclusively: one or several sources of SiO₂, at least onesource of one or several trivalent elements X, one or several sources oforganic cation R, one or several sources of hydroxide anions, and water,and it has a composition, in terms of molar ratios, between theintervals

R⁺/SiO₂=0.01-1.0,

X₂O₃/SiO₂=0-0.1, excluding the value 0,

OH⁻/SiO₂=0-3.0, excluding the value 0, and

H₂O/SiO₂=1-50.

According to this embodiment, if you add to a reaction mixture, at leastone source of GeO₂, the composition, in terms of molar ratios will bebetween the intervals

GeO₂/SiO₂=0 and 0.5, excluding the value 0

R⁺/(SiO₂+GeO₂)=0.01-1.0,

X₂O₃/(SiO₂+GeO₂)=0-0.1, excluding the value 0,

OH⁻/(SiO₂+GeO₂)=0-3.0, excluding the value 0, and

H₂O/(SiO₂+GeO₂)=1-50.

According to a particular embodiment the reaction mixture comprisesexclusively: one or several sources of SiO₂,

at least one source of one or several trivalent elements X

one or several sources of organic cation R,

one or several sources of fluoride anions, and

water,

and has a composition, in terms of molar ratios, between the intervals

R⁺/SiO₂=0.01-1.0,

X₂O₃/SiO₂=0-0.1, excluding the value 0,

F⁻/SiO₂=0-3.0, excluding the value 0, and

H₂O/SiO₂=1-50.

According to this embodiment, if to reaction mixture you add, at leastone source of GeO₂, the composition, in terms of molar ratios will bebetween the intervals

GeO₂/SiO₂=0 and 0.5, excluding the value 0

R⁺/(SiO₂+GeO₂)=0.01-1.0,

X₂O₃/(SiO₂+GeO₂)=0-0.1, excluding the value 0,

F⁻/(SiO₂+GeO₂)=0-3.0, excluding the value 0, and

H₂O/(SiO₂+GeO₂)=1-50.

According to another preferred embodiment, in the method previouslydescribed, the reaction mixture may also include, at least one source ofother tetravalent elements Y, different from Si and Ge.

According to one particular embodiment, the reaction mixture comprisesexclusively: one or several sources of SiO₂, at least one source of oneor several tetravalent elements Y, one or several sources of organiccation R, at least one source of anions selected between hydroxideanions, fluoride anions and combinations of them, and water, and it hasa composition, in terms of molar ratios, between the intervals

R⁺/SiO₂=0.01-1.0,

YO₂/SiO₂=0-0.1, excluding the value 0,

OH⁻/SiO₂=0-3.0,

F⁻/SiO₂=0-3.0

(OH⁻+F⁻)/SiO₂=0-3.0, excluding the value 0, and

H₂O/SiO₂=1-50.

According to this embodiment, if to the reaction mixture you add, atleast one source of GeO₂, the composition, in terms of molar ratios willbe between the intervals

GeO₂/SiO₂=0 and 0.5, excluding the value 0

R⁺/(SiO₂+GeO₂)=0.01-1.0,

YO₂/(SiO₂+GeO₂)=0-0.1, excluding the value 0,

OH⁻/(SiO₂+GeO₂)=0-3.0,

F⁻/(SiO₂+GeO₂)=0-3.0

(OH⁻+F⁻)/(SiO₂+GeO₂)=0-3.0, excluding the value 0, and

H₂O/(SiO₂+GeO₂)=1-50.

According to another particular embodiment of the method, the reactionmixture comprises exclusively: one or several sources of SiO₂, at leasta source of one or several tetravalent elements Y one or several sourcesof organic cation R, one or several sources of hydroxide anions, andwater, and it has a composition, in terms of molar ratios, between theintervals

R⁺/SiO₂=0.01-1.0,

YO₂/SiO₂=0-0.1, excluding the value 0,

OH⁻/SiO₂=0-3.0, excluding the value 0, and

H₂O/SiO₂=1-50.

According to this embodiment, if you add to the reaction mixture, atleast one source of GeO₂, the composition, in terms of molar ratios willbe between the intervals

GeO₂/SiO₂=0 and 0.5, excluding the value 0

R⁺/(SiO₂+GeO₂)=0.01-1.0,

YO₂/(SiO₂+GeO₂)=0-0.1, excluding the value 0,

OH⁻/(SiO₂+GeO₂)=0-3.0, excluding the value 0, and

H₂O/(SiO₂+GeO₂)=1-50.

According to another particular embodiment of the method, the reactionmixture comprises exclusively: one or several sources of SiO₂, at leastone source of one or several tetravalent elements Y, one or severalsources of organic cation R, one or several sources of fluoride anions,and water, and it has a composition, in terms of molar ratios, betweenthe intervals

R⁺/SiO₂=0.01-1.0,

YO₂/SiO₂=0-0.1, excluding the value 0,

F⁻/SiO₂=0-3.0, excluding the value 0, and

H₂O/SiO₂=1-50.

According to this embodiment, if you add to the reaction mixture, atleast one source of GeO₂, the composition, in terms of molar ratios willbe between the intervals

GeO₂/SiO₂=0 and 0.5, excluding the value 0

R⁺/(SiO₂+GeO₂)=0.01-1.0,

YO₂/(SiO₂+GeO₂)=0-0.1, excluding the value 0,

F⁻/(SiO₂+GeO₂)=0-3.0, excluding the value 0, and

H₂O/(SiO₂+GeO₂)=1-50.

According to another particular embodiment of the described method, thereaction mixture may include one or several sources of several trivalentelements X as well as one or several sources of one or severaltetravalent elements.

According to one particular embodiment, the reaction mixture comprisesexclusively: one or several sources of SiO₂, at least one source of oneor several trivalent elements X, at least one source of one or severaltetravalent elements Y, and/or several sources of organic cation R, atleast one source of anions selected among hydroxide anions, fluorideanions and combinations of the same, and water, and the reaction mixturehas a composition, in terms of molar ratios, between the intervals

R⁺/SiO₂=0.01-1.0,

X₂O₃/SiO₂=0-0.1, excluding the value 0,

YO₂/SiO₂=0-0.1, excluding the value 0,

OH⁻/SiO₂=0-3.0

F⁻/SiO₂=0-3.0

(OH⁻+F⁻)/SiO₂=0-3.0, excluding the value 0, and

H₂O/SiO₂=1-50

According to this embodiment, if you add to the reaction mixture, atleast one source of GeO₂, the composition, in terms of molar ratios willbe between the intervals

GeO₂/SiO₂=0 and 0.5, excluding the value 0

R⁺/(SiO₂+GeO₂)=0.01-1.0,

X₂O₃/(SiO₂+GeO₂)=0-0.1, excluding the value 0,

YO₂/(SiO₂+GeO₂)=0-0.1, excluding the value 0,

OH⁻/(SiO₂+GeO₂)=0-3.0

F⁻/(SiO₂+GeO₂)=0-3.0

(OH⁻+F⁻)/(SiO₂+GeO₂)=0-3.0, excluding the value 0, and

H₂O/(SiO₂+GeO₂)=1-50

According to another particular embodiment the reaction mixturecomprises exclusively: one or several sources of SiO₂, at least onesource of one or several trivalent elements X, at least one source ofone or several tetravalent elements Y, one or several sources of organiccation R, one or several sources of hydroxide anions, and water, and ithas a composition, in terms of molar ratios, between the intervals

R⁺/SiO₂=0.01-1.0,

X₂O₃/SiO₂=0-0.1, excluding the value 0,

YO₂/SiO₂=0-0.1, excluding the value 0,

OH⁻/SiO₂=0-3.0, excluding the value 0, and

H₂O/SiO₂=1-50.

According to this embodiment, if you add to the reaction mixture, atleast one source of GeO₂, the composition, in terms of molar ratios willbe between the intervals

GeO₂/SiO₂=0 and 0.5, excluding the value 0

R⁺/(SiO₂+GeO₂)=0.01-1.0,

X₂O₃/(SiO₂+GeO₂)=0-0.1, excluding the value 0,

YO₂/(SiO₂+GeO₂)=0-0.1, excluding the value 0,

OH⁺/(SiO₂+GeO₂)=0-3.0, excluding the value 0, and

H₂O/(SiO₂+GeO₂)=1-50.

According to another particular embodiment the reaction mixturecomprises exclusively: one or several sources of SiO₂, at least onesource of one or several trivalent elements X, at least one source ofone or several tetravalent elements Y, one or several sources of organiccation R, one or several sources of fluoride anions, and water, and ithas a composition, in terms of molar ratios, between the intervals

R⁺/SiO₂=0.01-1.0,

X₂O₃/SiO₂=0-0.1, excluding the value 0,

YO₂/SiO₂=0-0.1, excluding the value 0,

F⁻/SiO₂=0-3.0 excluding the value 0, and

H₂O/SiO₂=1-50

According to this embodiment, if you add to the reaction mixture, atleast one source of GeO₂, the composition, in terms of molar ratios willbe between the intervals

GeO₂/SiO₂=0 and 0.5, excluding the value 0

R⁺/(SiO₂+GeO₂)=0.01-1.0,

X₂O₃/(SiO₂+GeO₂)=0-0.1, excluding the value 0,

YO₂/(SiO₂+GeO₂)=0-0.1, excluding the value 0,

F⁻/(SiO₂+GeO₂)=0-3.0 excluding the value 0, and

H₂O/(SiO₂+GeO₂)=1-50.

According to the method previously described, the reaction mixture caninclude, also, a source of inorganic cations M of charge +n, selectedamong H+, at least one inorganic cation of charge +n selected betweenalkaline, alkaline earth metals and combinations of the same, and amixture of both.

According to a preferred embodiment of the described method, the cationR can beN²,N²,N²,N⁵,N⁵,N⁵,3a,6a-octamethyloctahydropentalene-2,5-diammonium. Ina general manner, one may say that the reaction mixture can have acomposition, in terms of molar ratios, between the intervals

GeO₂/SiO₂=0 and 0.5,

R⁺/(SiO₂+GeO₂)=0.01-1.0,

M^(+n)/(SiO₂+GeO₂)=0-1.0

OH⁻/(SiO₂+GeO₂)=0-3.0

F⁻/(SiO₂+GeO₂)=0-3.0

(F⁻+OH)/(SiO₂+GeO₂)=0-3,

X₂O₃/(SiO₂+GeO₂)=0-0.1,

YO₂/(SiO₂+GeO₂)=0-0.1, and

H₂O/(SiO₂+GeO₂)=1-50.

According to one particular embodiment, the composition of the reactionmixture that gives rise to obtaining the ITQ-55 material may representin a general way the following formula with the values of the parametersthat are indicated in terms of molar ratios:rR_(1/p)(OH):sM_(1/n)OH:tX₂O₃ :uYO₂ :vF:gGeO₂:(1−g)SiO₂ :wH₂O

where M is one or several inorganic cations of charge +n; preferablyalkaline or alkaline earth, X is one or several trivalent elements,preferably Al, B, Ga, Fe, Cr or mixtures of them; Y is one or severaltetravalent elements different from Si, preferably Zr, Ti, Sn, V ormixtures of them; R is one or more organic cations, p is the charge ofthe cation or the average charge of the cations, preferablyN²,N²,N²,N⁵,N⁵,N⁵,3a,6a-octamethylo-octahydropentalene-2,5-diammonium; Fis one or more sources of fluoride ions, preferably HF, NH₄F, or amixture of both, and the values of g, r, s, t, u, v and w vary in theintervals:

g=0-0.5, preferably 0-0.33

r=ROH/SiO₂=0.01-1.0, preferably 0.1-1.0

s=M_(1/n)OH/SiO₂=0-1.0, preferably 0-0.2

t=X₂O₃/SiO₂=0-0.1, preferably 0-0.05

u=YO₂/SiO₂=0-0.1, preferably 0-0.05

v=F/SiO₂=0-3.0, preferably 0-2.0

w=H₂O/SiO₂=1-50, preferably 1-20

The components of the synthesis mixture may come from different sources,and depending on these, the times and crystallization conditions mayvary.

Preferably the thermal treatment of the mixture is carried out at atemperature between 110 and 200° C. The thermal treatment of thereaction mixture can be carried out as static or with stirring of themixture. Once the crystallization is concluded the solid product isseparated by filtration or centrifuging and dried. The subsequentcalcining at temperatures greater than 350° C., preferably between 400and 1300° C., and more preferably between 600 and 1000° C., produces thedecomposition of the organic remnants occluded within the zeolite andtheir expulsion, leaving the zeolitic channels clear.

The source of SiO₂ may be, for example, tetraethylorthosilicate,colloidal silica, amorphous silica and mixtures thereof.

The fluoride anion may be used as mobilizing agent of the precursorspecies. The source of fluoride ions is preferably HF, NH₄F or a mixtureof both.

The organic cation(s), represented by R, are added to the reactionmixture preferably in hydroxide form, of another salt, for example, ahalide, and a hydroxide mixture and another salt, that is to sayadditionally, a source may be added of alkaline, alkaline earth ions, ormixtures of both (M), in hydroxide form or in salt form.

In a preferred way the organic cation R isN²,N²,N²,N⁵,N⁵,N⁵,3a,6a-octamethyloctahydropentalene-2,5-diammonium, andit is added preferably in a form selected between hydroxide, anothersalt and a hydroxide mixture and another salt, preferably a halide.

The organic cationN²,N²,N²,N⁵,N⁵,N⁵,3a,6a-octamethylo-octahydropentalene-2,5-diammonium issynthesized following the process represented in the following outline:

In this process a aldolic condensation reaction is carried out followedby a decarboxylation reaction between the dimethyl1,3-acetonadicarboxylate with 2,3-butanodione to give rise to thecorresponding diketone,3a,6a-dimethyltetrahydropentalene-2,5(1H,3H)-dione. The diketone istransformed into the corresponding diamine by means of a reductiveamination reaction in the presence of dimethylamine and using sodiumcyanoborohydride as reducer, giving rise to the diamine,N²,N²,N⁵,N⁵,3a,6a-hexamethyloctahydropentalene-2,5-diamine. This diamineis subsequently quaternized with methyl iodide to give rise to the saltof N²,N²,N²,N⁵,N⁵,N⁵,3a,6a-octamethyloctahydropentalene-2,5-diammoniumdiiodide.

The salt of dialkylammonium diodide may be dissolved in water andexchanged with its hydroxide form using an anionic exchange resin inhydroxide form.

According to one particular embodiment of the method, a quantity isadded to the reaction mixture of microporous crystalline material,ITQ-55, from this invention as promoter of the crystallization in aquantity between 0.01 and 20% by weight, preferably between 0.05 and 10%by weight with regard to the total of added inorganic oxides.

Also, the material produced by means of this invention may be pelletizedin accordance with well-known techniques.

This invention also refers to the use of the microporous crystallinematerial previously described and obtained according to the processpreviously described.

The material of this invention, may be used as a catalyst or componentof catalysts in transformation processes of organic compounds, or asadsorbent in adsorption and separation processes of organic compounds.

For its use in the previously mentioned processes it is preferable thatITQ-55 is in its calcined form without organic matter in its interior.

The ITQ-55 material used in these catalytic applications may be in itsacidic form and/or exchanged with appropriate cations, such as H⁺ and/oran inorganic cation of charge +n, selected among alkaline,alkaline-earth metals, lanthanides and combinations thereof.

The ITQ-55 material used in adsorption/separation processes may be inits purely siliceous form, that is to say, not containing elements otherthan silicon and oxygen in its composition.

The ITQ-55 material used in adsorption/separation processes may be insilica-germania form, that is to say, not containing elements other thansilicon, germanium and oxygen in its composition.

The ITQ-55 material is particularly appropriate for use as selectiveadsorbent of CO₂ in the presence of hydrocarbons, preferably methane,ethane, ethylene and combinations of the same, in streams that containthese gases, well as adsorbent in powdered or pelletized form or inmembrane form.

According to one specific embodiment, the ITQ-55 material may be usedfor the separation of CO₂ and methane.

According to one specific embodiment, the ITQ-55 material may be usedfor the separation of CO₂ and ethane.

According to one specific embodiment, the ITQ-55 material may be usedfor the separation of CO₂ and ethylene.

According to another particular embodiment, the ITQ-55 material isparticularly appropriate for the separation in adsorption processes ofhydrocarbons of 1 or 2 carbon atoms that contain these gases, as well asadsorbent in powdered or pelletized form or in membrane form.

According to one specific embodiment, the ITQ-55 material is used as aselective adsorbent of ethylene in the presence of ethane.

According to another specific embodiment, the ITQ-55 material is used asselective adsorbent of ethylene in the presence of methane.

Throughout the description and the claims the word “includes” and itsvariants does not seek to exclude other technical characteristics,additives, components or steps. For the experts in the matter, otherobjects, advantages and characteristic of the invention shall comepartly from the description and partly from the practice of theinvention.

Separation Process and Method of Use Overview

In this discussion, a fluid is defined as a gas or a liquid, includingmixtures of both gas and liquid. In this discussion, ambient temperaturegenerally refers to a pressure of about 1 atmosphere (about 101 kPa) anda temperature of about 20° C.

In various aspects, processes are provided that implement a molecularsieve corresponding to zeolite ITQ-55 as described herein for adsorptionand/or separation of components of fluid streams, such as gas streams,liquid streams, or streams corresponding to a mixture of gas and liquid.The zeolite ITQ-55 can be suitable for separating a variety of smallmolecules and/or noble gases. At some temperatures, a molecular sievecorresponding to zeolite ITQ-55 can be suitable for adsorbing a varietyof small molecules while reducing, minimizing, or even substantiallyeliminating adsorption of methane and other compounds containing atleast one methyl group. For example, zeolite ITQ-55 can be suitable forperforming separations to separate H₂, N₂, or CO₂ from methane. Avariety of other types of fluid separations can also be performeddepending on the composition of an input gas and the temperature andpressure during the separation process.

The pore structure of zeolite ITQ-55 includes 8-member ring channels.The 8-member ring channels include a minimum pore channel size in thepore network of 5.9 Angstroms×2.1 Angstroms at ambient temperature. Thisminimum pore channel size can limit the types of compounds that caneffectively enter and/or pass through the pore network. However, the8-member ring that provides the minimum size is also believed to haveflexibility. This flexibility can allow the 8-member ring to deform,such as due to thermal fluctuations and/or due to fluctuations inducedat elevated pressures, which can lead to a potential temporary change inthe size of the pore channel. Without being bound by any particulartheory, it is believed that the flexibility of the 8-member ringdefining the size of the pore channel can allow for additional tuning ofseparations of various compounds based on temperature and/or pressure.

Additionally or alternately, the particle size of ITQ-55 crystals usedin an adsorbent structure or membrane structure can have an impact onthe ability of the adsorbent structure or membrane structure to performa separation. As one example, the particle size of the ITQ-55 crystalscan have an influence on the amount of “dead space” that is present atthe surface and/or within the interior of an adsorbent structure ormembrane structure. Mathematically, the packing density of a collectionof hard spheres of similar size is dependent on the radius of thespheres. For a collection of hard spheres, the larger the averageradius, the larger the size of the spaces or gaps between the hardspheres. Without being bound by any particular theory, it is believedthat for a collection of ITQ-55 crystals of similar size, the size ofthe voids or dead spaces created after close packing of crystals can berelated to the average particle size. Having a smaller particle size canreduce such dead space, thus providing an increased pore surface areafor accepting fluid components for separation.

Additionally or alternately, the composition of ITQ-55 crystals used inan adsorbent structure or membrane structure can have an impact on theability of the adsorbent structure or the membrane structure to performa separation. In some aspects, ITQ-55 can be synthesized to have aframework structure composed of primarily silicon and oxygen. In otheraspects, a portion of the framework atoms in the ITQ-55 structure can bereplaced with other elements. For example, a portion of the silicon inthe framework structure can be replaced with atoms from a differentgroup in the periodic table, such as Al, P, or B. As another example, aportion of the silicon in the framework can be replaced with atoms froma different row of the periodic table, such as Ge or P. Such compositionvariations can modify the size of the pores within the crystal structureand/or modify the affinity of the ITQ-55 relative to one or morepotential components for adsorption. Such modifications of pore sizeand/or affinity can potentially improve selectivity (such as kineticselectivity) for one or more types of separation.

Zeolite ITQ-55 can be used to separate components in a fluid stream (forexample, a gas stream) in various manners. In some aspects, zeoliteITQ-55 can be used to form a membrane structure, so that separation offluid components is performed by forming a permeate and a retentateportion of a fluid on respective sides of the membrane. Zeolite ITQ-55can assist with such a membrane separation, for example, by havingvarying selectivities for allowing fluid components to pass through themembrane.

In other aspects, zeolite ITQ-55 can be used to form an adsorbentstructure within a separation vessel, so that separation of fluidcomponents can be performed by adsorbing a portion of a fluid streamwithin the adsorbent structure while allowing a remainder of the fluidstream to exit from the separation vessel. The adsorbent structure canbe composed of the zeolite ITQ-55, or the zeolite ITQ-55 can form acoating as part of an adsorbent structure, so that molecules can passthrough the pores of ITQ-55 crystals in order to enter the underlyingstructure. The zeolite ITQ-55 can assist with performing separationsusing such an adsorbent structure, for example, by having varyingselectivities for allowing fluid components to enter the adsorbentstructure.

In still other aspects, zeolite ITQ-55 can be used as part of a storagestructure for fluids, such as a storage structure within a storagevessel. A storage structure can in some aspects be similar to anadsorbent structure. However, the storage structure can be used in adifferent manner, so that gases (or more generally fluids) that enterthe storage structure can be retained for an extended period of time.The storage structure can be composed of the zeolite ITQ-55, or thezeolite ITQ-55 can form a coating for a storage structure, so thatmolecules can pass through the pores of ITQ-55 crystals in order toenter the storage structure. The zeolite ITQ-55 can assist with storageof fluid components using such a storage structure, for example, byhaving varying selectivities for allowing fluid components to enter thestorage structure. The zeolite ITQ-55 can potentially also assist withstorage of fluids using such a storage structure, for example, by havinga rate of transfer through the pore network that is greater at highertemperature and lower at reduced temperatures. The difference in rate oftransfer or movement within the pores of ITQ-55 can be enhanced by theflexible nature of the 8-member ring that defines the minimum pore sizefor ITQ-55.

Separation of Fluid Components

When a fluid stream is exposed to a membrane structure, adsorbentstructure, storage structure, or other porous structure that includeszeolite ITQ-55 as part of the surface of the structure, a selectiveseparation of components within the fluid stream may occur if one ormore of the components in the fluid stream has a sufficiently smallkinetic diameter.

Some fluid separations can be performed based on one component of afluid having a sufficiently small kinetic diameter to enter the pores ofzeolite ITQ-55 while a second component is too large to enter the porenetwork under the exposure conditions. For example, it has beendetermined that hydrocarbons having a terminal methyl group (includingmethane) and/or other hydrocarbons containing 3 or more carbon atomsgenerally have kinetic diameters that are too large to enter and/or passthrough the pore network of ITQ-55 at typical ambient conditions, suchas about 20° C. and about 0.1 MPaa. This is in contrast to compoundswith a smaller kinetic diameter, such as H₂ or N₂, which can enterand/or pass through the pore network. In this type of situation, aseparation can be performed with a high degree of selectivity, as theamount of hydrocarbon entering an ITQ-55 layer can be substantiallylimited to hydrocarbons that enter at a discontinuity in the ITQ-55layer, such as a mesopore or macropore at a crystal or grain boundary.

Other types of separations can be dependent on differences in uptake byzeolite ITQ-55 between two (or more) fluid components that havesufficiently small kinetic diameters to enter and/or pass through thepore network of ITQ-55. In this situation, separation of components inan input fluid stream can be performed based on a kinetic separation oran equilibrium separation of the components. The nature of theseparation can be dependent on, for example, the relative kineticdiameters of the components and/or the relative affinities of thecomponents for the ITQ-55.

One example of a process where the relationship between the kineticdiameters and/or affinities of molecules and the size of the porenetwork of a zeolite can be relevant is in selective adsorption ofcomponents from a fluid stream. In equilibrium controlled adsorptionprocesses, most of the selectivity is imparted by the equilibriumadsorption properties of the adsorbent, and the competitive adsorptionisotherm of a first fluid component in the micropores or free volume ofthe adsorbent is not favored relative to a second component. Inkinetically controlled processes, most of the selectivity is imparted bythe diffusional properties of the adsorbent and the transport diffusioncoefficient in the micropores and free volume of the competing adsorbedcomponents. In some kinetically controlled processes, a component with ahigher diffusivity can be preferentially adsorbed relative to acomponent with a lower diffusivity. Additionally or alternately, therelative affinity of competing adsorbed components for ITQ-55 can be afactor, which may alter the selectivity for separation of componentsrelative to an expected selectivity based just on diffusivity. Also, inkinetically controlled processes with microporous adsorbents,diffusional selectivity can arise from diffusion differences in themicropores of the adsorbent and/or from selective diffusional surfaceresistance in the crystals or particles that make-up the adsorbent.

Unless otherwise noted, the term “adsorbent selectivity” as used hereinis based on binary (pairwise) comparison of the molar concentration ofcomponents in the feed stream and the total number of moles of each ofthese components that are adsorbed by the particular adsorbent duringthe adsorption step of a process cycle (such as a swing adsorptionprocess cycle) under the specific system operating conditions andfeedstream composition. For a feed containing component A, component B,as well as additional components, an adsorbent that has a greater“selectivity” for component A than component B will have at the end ofthe adsorption step of a process cycle a ratio: U_(A)=(total moles of Ain the adsorbent)/(molar concentration of A in the feed) that is greaterthan the ratio: U_(B)=(total moles of B in the adsorbent)/(molarconcentration of B in the feed), where U_(A) is the “Adsorption Uptakeof component A” and U_(B) is the “Adsorption Uptake of component B”.Therefore for an adsorbent having a selectivity for component A overcomponent B that is greater than one: Selectivity=U_(A)/U_(B) (whereU_(A)>U_(B)). Amongst a comparison of different components in the feed,the component with the smallest ratio of the total moles picked up inthe adsorbent to its molar concentration in the feed can be referred toas the “lightest” component in the swing adsorption process, while thecomponent with the largest ratio of the total moles picked up in theadsorbent to its molar concentration in the feed can be referred to asthe “heaviest” component. This means that the molar concentration of thelightest component in the stream coming out during the adsorption stepis greater than the molar concentration of that lightest component inthe feed.

In some aspects, the selectivity of an adsorbent can additionally oralternatively be characterized based on a “kinetic selectivity” for twoor more fluid components. As used herein, the term “kinetic selectivity”is defined as the ratio of single component diffusion coefficients, D(in m²/sec), for two different species. These single component diffusioncoefficients are also known as the transport diffusion coefficients thatare measured for a given adsorbent for a given pure gas component.Therefore, for example, the kinetic selectivity for a particularadsorbent for component A with respect to component B would be equal toD_(A)/D_(B). The single component diffusion coefficients for a materialcan be determined by tests well known in the adsorptive materials art.The preferred way to measure the kinetic diffusion coefficient is with afrequency response technique described by Reyes et al. in “FrequencyModulation Methods for Diffusion and Adsorption Measurements in PorousSolids”, J. Phys. Chem. B. 101, pages 614-622, 1997.

In other aspects, the selectivity of an adsorbent can additionally oralternatively be characterized based on an “equilibrium selectivity” fortwo or more fluid components. As used herein, the term “equilibriumselectivity” is defined in terms of the slope of the single componentuptake into the adsorbent (in μmol/g) vs. pressure (in torr) in thelinear portion, or “Henry's regime”, of the uptake isotherm for a givenadsorbent for a given pure component. The slope of this line is calledherein the Henry's constant or “equilibrium uptake slope”, or “H”. The“equilibrium selectivity” is defined in terms of a binary (or pairwise)comparison of the Henrys constants of different components in the feedfor a particular adsorbent. Therefore, for example, the equilibriumselectivity for a particular adsorbent for component A with respect tocomponent B would be H_(A)/H_(B).

Another example of a process where the relationship between the kineticdiameters of molecules (or atoms), affinities of molecules (or atoms)for ITQ-55, and the size of the pore network of a zeolite can berelevant is in selective separation of components from a fluid streamusing a membrane. Membrane separations can primarily be performed basedon the kinetic selectivity of a membrane. Unlike an adsorbent, any fluidcomponents passing through a membrane to form a permeate can be removedperiodically or continuously. For example, the permeate side of themembrane can be exposed to a sweep stream. This can prevent asubstantial concentration of a component from accumulating on thepermeate side of a membrane, so that transport of a fluid component ofinterest from the retentate side to the permeate side is enhanced ormaximized.

Unless otherwise noted, the term “membrane selectivity” as used hereinis based on binary (pairwise) comparison of the molar concentration ofcomponents in the feed stream and the total number of moles of thesecomponents that pass through the membrane to form a permeate during amembrane separation under the specific system operating conditions andfeedstream composition. For a feed containing component A, component B,as well as additional components, a membrane that has a greater“selectivity” for component A than component B will have at varioustimes during the membrane separation and/or at the end of the membraneseparation a ratio: X_(A)=(molar concentration of A in thepermeate)/(molar concentration of A in the feed) that is greater thanthe ratio: X_(B)=(molar concentration of B in the permeate)/(molarconcentration of B in the feed). Therefore, for a membrane having aselectivity for component A over component B that is greater than one, aselectivity can be defined as Selectivity=X_(A)/X_(B) (whereX_(A)>X_(B)).

Still another example of a process where the relationship between thekinetic diameters of molecules (or atoms), the affinities of themolecules (or atoms) for ITQ-55, and the size of the pore network of azeolite can be relevant is in storage of a fluid component. In a storagesituation, if a fluid component for storage is exposed to a storage(adsorbent) structure as part of a substantially pure stream of thefluid component, the kinetic diameter of a component and/or relativeaffinity of a component for ITQ-55 may be less important so long as thecomponent can enter the pore network. However, if the fluid componentfor storage is introduced as part of a multi-component stream, theability to load the storage structure can be dependent on theselectivity of the storage structure (either kinetic or equilibrium) forthe desired component. Additionally, during a storage period, theability to modify the storage conditions for the storage structure canbe beneficial in retaining a fluid component within the storagestructure, such as by reducing or minimizing the ability of thecomponent to exit the storage structure during the storage period.

Based on the minimum 8-member ring size in the pore network of zeoliteITQ-55, fluid components that can be adsorbed and/or separated using thezeolite at ambient conditions (i.e., 20° C. and 0.1 MPaa) can correspondto components with relatively small kinetic diameters, such as kineticdiameters of about 0.40 nm or less, or about 0.38 nm or less. Thefollowing list of molecules (and noble gas atoms) provides a listing ofcomponents that can be adsorbed and/or separated using zeolite ITQ-55.The following list is not intended to be exhaustive. The listing isroughly based on previously determined values of kinetic diameters forthe listed components. It is noted that many of these previouslydetermined values are based an assumption of a spherical molecule. As aresult, the order shown in the following list may not necessarilycorrespond to the actual kinetic selectivity. For example, literaturevalues for the kinetic diameter of H₂O and H₂ are similar, with H₂Osometimes having a smaller kinetic diameter as shown in the list.However, in practice H₂ may be kinetically favored for adsorption undersome adsorption and/or separation conditions.

The following molecules and atoms are generally below methane in kineticdiameter: He, H₂O, H₂, Ne, N₂O, NO, HCl, Cl₂, CO₂, C₂H₂, Ar, NO₂, O₂,Br₂, HBr, NH₃, H₂S, SO₂, CS₂, Kr, N₂, CO. In addition to this list, itis noted that ethylene and formaldehyde, which have apparent kineticdiameters (under an assumption of a spherical molecule) larger thanmethane, can also be adsorbed and/or separated by zeolite ITQ-55. It isnoted that ethylene and formaldehyde are effectively planar molecules,and therefore the assumption of a spherical molecule is lessappropriate. Similarly, molecules like acetylene are less wellrepresented by a spherical molecule assumption. Without being bound byany particular theory, it is believed that the kinetic diameter formethane is similar to 0.38 nm or 0.40 nm along any axis of methane, dueto the roughly spherical shape of a methane molecule (based on thetetrahedral symmetry). By contrast, the kinetic diameter of moleculessuch as acetylene, ethylene, and formaldehyde is believed to varydepending on the orientation of the molecule. Thus, even though theapparent kinetic diameters of ethylene and formaldehyde (under theassumption of spherical molecules) may be greater than methane, aproperly oriented ethylene or formaldehyde molecule can present asmaller kinetic cross-section, which can allow these molecules to enteran ITQ-55 pore network.

In some aspects, it can be desirable to use zeolite ITQ-55 foradsorption and/or separation of components where the zeolite ITQ-55 canprovide sufficient selectivity between components. For example, use ofITQ-55 can provide a selectivity for a first fluid component over asecond fluid component, either for adsorption or for separation viamembrane, of at least about 5, or at least about 10, or at least about20, or at least about 30.

Examples of separations that can be performed (either via adsorption ormembrane separation) include, but are not limited to:

a) Separation of CO₂ and/or CO from hydrocarbons, alcohols, and/or otherorganic compounds having three or more heavy (non-hydrogen) atoms, suchas CO₂ and/or CO from methane, ethane, ethylene, acetylene, natural gas,flue gas, natural gas liquids, or a combination thereof. Due to the lowor minimal adsorption of hydrocarbons by ITQ-55, this separation can beperformed under any convenient conditions, so long as the temperature islow enough to substantially minimize adsorption of hydrocarbons.

b) Separation of CO₂ and/or CO from nitrogen. Optionally, thisseparation can be performed at temperatures below (or substantiallybelow) 0° C. and at low to moderate pressures to further improve theselectivity of the separation under either kinetic separation conditionsor equilibrium separation conditions.

c) Separation of ethylene, formaldehyde, and/or acetylene from organiccompounds having three or more heavy (non-hydrogen) atoms. Due to thelow or minimal adsorption of larger hydrocarbons and/or organiccompounds by ITQ-55, this separation can be performed under anyconvenient conditions, so long as the temperature is low enough tosubstantially minimize adsorption of the larger hydrocarbons and/ororganic compounds.

d) Separation of acetylene from ethylene, methane, and/or ethane.

e) Separation of NO₂ and/or SO₂ from flue gas. Flue gas can contain avariety of hydrocarbons. Due to the low or minimal adsorption ofhydrocarbons by ITQ-55, this separation can be performed under anyconvenient conditions, so long as the temperature is low enough tosubstantially minimize adsorption of hydrocarbons.

f) Separation of NO₂ from SO₂. This separation can optionally beperformed at ambient temperature or greater as a kinetic separation oran equilibrium separation. Alternatively, the separation can beperformed at temperatures less than ambient.

g) Separation of HCl, HBr, Cl₂, and/or Br₂ from other components.

h) Separation of N₂ from methane, natural gas, natural gas liquids(C₂+), other hydrocarbons, and/or other organic compounds having threeor more heavy atoms (i.e., atoms other than hydrogen). Due to the low orminimal adsorption of hydrocarbons by ITQ-55, this separation can beperformed under any convenient conditions, so long as the temperature islow enough to substantially minimize adsorption of hydrocarbons.Additionally or alternately, the separation can be performed at anyconvenient operating conditions based on kinetic selectivity. This canbe in contrast to conventional methods for separation of N₂ fromhydrocarbons or organic compounds, as conventional methods often involveseparation at cryogenic conditions. It is noted that for natural gas,separation of N₂, H₂S, and/or CO₂ from natural gas can be performedprior to liquefying the natural gas, after liquefying the natural gas,or a combination thereof.

i) Separation of O₂ from N₂ or air. This separation can optionally beperformed at ambient temperature or greater as a kinetic separation oran equilibrium separation, or optionally at temperatures below ambient.In some aspects, the separation conditions can be in contrast toconventional methods for separation of O₂ from N₂ or air, asconventional methods often involve separation at cryogenic conditions.

j) Syngas separations. One example is a separation of methane from othersyngas components, such as CO, CO₂, and H₂, which can be facilitated bythe reduced or minimized adsorption of methane by ITQ-55. Anotherexample is separation of H₂ from other syngas components, which canoptionally be performed as a kinetic separation due to the small kineticdiameter of H₂. Optionally, water can be separated from syngas (such asby reducing the temperature to separate water as a liquid) to improvethe selectivity for forming an H₂ product stream.

k) Separation of CO from methane and/or other compounds. Due to the lowor minimal adsorption of hydrocarbons by ITQ-55, separation from typicalhydrocarbons and/or organic compounds can be performed under anyconvenient conditions, so long as the temperature is low enough tosubstantially minimize adsorption of hydrocarbons.

l) Separation of H₂ from water, hydrocarbons, N₂, CO₂, NH₃, CO, othergas components, or a combination thereof.

m) Separation of He from water, hydrocarbons, natural gas, N₂, CO₂, CO,other gas components, or a combination thereof.

n) Separation of Ne, Ar, and/or Kr from air and/or other gas components.

o) Separation of NH₃ from components with a larger kinetic diameterand/or lower affinity for ITQ-55.

p) Separation of CO₂ from methane and other higher molecular weighthydrocarbons in a natural gas feedstream.

q) Separation of H₂O from methane and other higher molecular weighthydrocarbons in a natural gas feedstream.

r) Separation of N₂ from methane and other higher molecular weighthydrocarbons in a natural gas feedstream.

s) Separation of H₂O, N₂, or a combination thereof from methane andother higher molecular weight hydrocarbons in a natural gas feedstream.

t) Separation of H₂S from methane and other higher molecular weighthydrocarbons in a natural gas feedstream.

u) Separation of CS₂ and/or COS from components with a larger kineticdiameter.

v) Separation of methanol and/or dimethyl ether from higher molecularweight hydrocarbons and organic compounds.

w) Separation of methanol and/or dimethyl ether from methane, ethane,ethylene, acetylene, and/or formaldehyde.

x) Separation of methane or ethane from higher molecular weighthydrocarbons and organic compounds.

y) Separation of H₂S and/or H₂O from methane and/or other highermolecular weight hydrocarbons and/or other organic compounds havingthree or more heavy (non-hydrogen) atoms.

Adsorbent Separations (Including Swing Processing)

Gas separation (or other fluid separation) is important in variousindustries and can typically be accomplished by flowing a mixture ofgases over an adsorbent that preferentially adsorbs a more readilyadsorbed component relative to a less readily adsorbed component of themixture. Swing adsorption is an example of a commercially valuableseparation technique, such as pressure swing adsorption (PSA) ortemperature swing adsorption (TSA). PSA processes rely on the fact thatunder pressure fluids tend to be adsorbed within the pore structure of amicroporous adsorbent material or within the free volume of a polymericmaterial. The higher the pressure, the more fluid is adsorbed. When thepressure is reduced, the fluid is released, or desorbed. PSA processescan be used to separate fluids in a mixture because different fluidstend to fill the micropore or free volume of the adsorbent to differentextents. If a gas mixture, such as natural gas, for example, is passedunder pressure through a vessel containing polymeric or microporousadsorbent that fills with more nitrogen than it does methane, part orall of the nitrogen will stay in the adsorbent bed, and the gas comingout of the vessel will be enriched in methane. When the adsorbent bedreaches the end of its capacity to adsorb nitrogen, it can beregenerated by reducing the pressure, thereby releasing the adsorbednitrogen. It is then ready for another cycle.

Another important fluid separation technique is temperature swingadsorption (TSA). TSA processes also rely on the fact that underpressure fluids tend to be adsorbed within the pore structure of amicroporous adsorbent material or within the free volume of a polymericmaterial. When the temperature of the adsorbent is increased, the fluidis released, or desorbed. By cyclically swinging the temperature ofadsorbent beds, TSA processes can be used to separate fluids in amixture when used with an adsorbent that selectively picks up one ormore of the components in the fluid mixture.

In addition to swings of pressure and/or temperature in order to formthe adsorbed product stream, formation of an adsorbed product stream canbe facilitated by exposing the adsorbent to a displacement fluid stream.After performing a separation by selectively adsorbing a component froman input stream, the selectively adsorbed component can be desorbed atleast in part by displacing the selectively adsorbed component withanother fluid component that has a greater affinity for adsorption. Thisadditional fluid component can be referred to as a displacement fluidcomponent. Optionally, the displacement fluid component can be readilyseparated from the selectively adsorbed component, such as bycondensation and/or phase separation.

Adsorbents for PSA systems are usually very porous materials chosenbecause of their large surface area. Typical adsorbents are activatedcarbons, silica gels, aluminas and zeolites. In some cases a polymericmaterial can be used as the adsorbent material. Though the fluidadsorbed on the interior surfaces of microporous materials may consistof a layer only one, or at most a few molecules thick, surface areas ofseveral hundred square meters per gram enable the adsorption of asignificant portion of the adsorbent's weight in gas. The molecularspecies that selectively fill the micropores or open volume of theadsorbent are typically referred to as the “heavy” components and themolecular species that do not selectively fill the micropores or openvolume of the adsorbent are usually referred to as the “light”components.

Various types swing adsorption can be used in the practice of thepresent invention. Non-limiting examples of such swing adsorptionprocesses include thermal swing adsorption (TSA) and various types ofpressure swing adsorption processes including conventional pressureswing adsorption (PSA), and partial pressure swing or displacement purgeadsorption (PPSA) technologies. These swing adsorption processes can beconducted with rapid cycles, in which case they are referred to as rapidcycle thermal swing adsorption (RCTSA), rapid cycle pressure swingadsorption (RCPSA), and rapid cycle partial pressure swing ordisplacement purge adsorption (RCPPSA) technologies. The term swingadsorption processes shall be taken to include all of these processes(i.e. TSA, PSA, PPSA, RCTSA, RCPSA, and RCPPSA) including combinationsof these processes. Such processes require efficient contact of a gasmixture with a solid adsorbent material.

Although any suitable adsorbent contactor can be used in the practice ofthe present invention, including conventional adsorbent contactors, insome aspects structured parallel channel contactors can be utilized. Thestructure of parallel channel contactors, including fixed surfaces onwhich the adsorbent or other active material is held, can providesignificant benefits over previous conventional gas separation methods,such as vessels containing adsorbent beads or extruded adsorbentparticles. With parallel channel contactors, total recovery of the lightcomponent (i.e., the component that is not preferentially adsorbed)achieved in a swing adsorption process can be greater than about 80 vol%, or greater than about 85 vol %, or greater than about 90 vol %, orgreater than about 95 vol % of the content of the light componentintroduced into the process. Recovery of the light component is definedas the time averaged molar flow rate of the light component in theproduct stream divided by the time averaged molar flow rate of the lightcomponent in the feedstream. Similarly, recovery of the heavy component(i.e., the component that is preferentially adsorbed) is defined as thetime averaged molar flow rate of the heavy component in the productstream divided by the time averaged molar flow rate of the heavycomponent in the feedstream.

The channels, also sometimes referred to as “flow channels”, “fluid flowchannels”, or “gas flow channels”, are paths in the contactor that allowgas or other fluids to flow through. Generally, flow channels providefor relatively low fluid resistance coupled with relatively high surfacearea. Flow channel length should be sufficient to provide the masstransfer zone which is at least, a function of the fluid velocity, andthe surface area to channel volume ratio. The channels are preferablyconfigured to minimize pressure drop in the channels. In manyembodiments, a fluid flow fraction entering a channel at the first endof the contactor does not communicate with any other fluid fractionentering another channel at the first end until the fractions recombineafter exiting at the second end. It is important that there be channeluniformity to ensure that substantially all of the channels are beingfully utilized, and that the mass transfer zone is substantially equallycontained. Both productivity and gas/fluid purity will suffer if thereis excessive channel inconsistency. If one flow channel is larger thanan adjacent flow channel, premature product break through may occur,which leads to a reduction in the purity of the product gas tounacceptable purity levels. Moreover, devices operating at cyclefrequencies greater than about 50 cycles per minute (cpm) requiregreater flow channel uniformity and less pressure drop than thoseoperating at lower cycles per minute. Further, if too much pressure dropoccurs across the bed, then higher cycle frequencies, such as on theorder of greater than 100 cpm, are not readily achieved.

The dimensions and geometric shapes of the parallel channel contactorscan be any dimension or geometric shape that is suitable for use inswing adsorption process equipment. Non-limiting examples of geometricshapes include various shaped monoliths having a plurality ofsubstantially parallel channels extending from one end of the monolithto the other; a plurality of tubular members; stacked layers ofadsorbent sheets with and without spacers between each sheet;multi-layered spiral rolls, bundles of hollow fibers, as well as bundlesof substantially parallel solid fibers. The adsorbent can be coated ontothese geometric shapes or the shapes can, in many instances, be formeddirectly from the adsorbent material plus suitable binder. An example ofa geometric shape formed directly from the adsorbent/binder would be theextrusion of a zeolite/polymer composite into a monolith. Anotherexample of a geometric shape formed directly from the adsorbent would beextruded or spun hollow fibers made from a zeolite/polymer composite. Anexample of a geometric shape that is coated with the adsorbent would bea thin flat steel sheet that is coated with a microporous, low mesopore,adsorbent film, such as a zeolite film. The directly formed or coatedadsorbent layer can be itself structured into multiple layers or thesame or different adsorbent materials. Multi-layered adsorbent sheetstructures are taught in United States Patent Application PublicationNo. 2006/0169142, which is incorporated herein by reference.

The dimensions of the flow channels can be computed from considerationsof pressure drop along the flow channel. It is preferred that the flowchannels have a channel gap from about 5 to about 1,000 microns,preferably from about 50 to about 250 microns. In some RCPSAapplications, the flow channels are formed when adsorbent sheets arelaminated together. Typically, adsorbent laminates for RCPSAapplications have flow channel lengths from about 0.5 centimeter toabout 10 meter, more typically from about 10 cm to about 1 meter and achannel gap of about 50 to about 250 microns. The channels may contain aspacer or mesh that acts as a spacer. For laminated adsorbents, spacerscan be used which are structures or material, that define a separationbetween adsorbent laminates. Non-limiting examples of the type ofspacers that can be used in the present invention are those comprised ofdimensionally accurate: plastic, metal, glass, or carbon mesh; plasticfilm or metal foil; plastic, metal, glass, ceramic, or carbon fibers andthreads; ceramic pillars; plastic, glass, ceramic, or metal spheres, ordisks; or combinations thereof. Adsorbent laminates have been used indevices operating at PSA cycle frequencies up to at least about 150 cpm.The flow channel length may be correlated with cycle speed. At lowercycle speeds, such as from about 20 to about 40 cpm, the flow channellength can be as long as or longer than one meter, even up to about 10meters. For cycle speeds greater than about 40 cpm, the flow channellength typically is decreased, and may vary from about 10 cm to about 1meter. Longer flow channel lengths can be used for slower cycle PSAprocesses. Rapid cycle TSA processes tend to be slower than rapid cyclePSA processes and as such longer flow channel lengths can also be usedwith TSA processes.

In various aspects, an adsorbent contactor can contain a very low volumefraction of open mesopores and macropores. For example, an adsorbentcontactor, such as a structured bed adsorbent contactor, can containless than about 20 vol %, or less than about 15 vol %, or less thanabout 10 vol %, or less than about 5 vol % of their pore volume in openpores in the mesopore and macropore size range. Mesopores are defined bythe IUPAC (and defined herein) to be pores with sizes in the 20 to 500angstrom size range. Macropores are defined herein to be pores withsizes greater than about 500 Angstroms and less than about 1 micron. Itis noted that flow channels within a contactor for allowing an input gas(or fluid) stream to be exposed to the contactor can typically be largerthan about 1 micron in size, and therefore are not considered to be partof the macropore volume. Open pores are defined mesopores and macroporesthat are not occupied by a blocking agent and that are capable of beingoccupied, essentially non-selectively, by components of a gas mixture.Different test methods as described below can be used to measure thevolume fraction of open pores in a contactor depending on the structureof the contactor.

The preferred test for determining the volume fraction of open mesoporesand macropores of the contactor is defined as follows and involving ananalysis of the isotherm of a condensable vapor adsorbed by thecontactor. A liquid which has a vapor pressure greater than about 0.1torr at the temperature of the test is a material that can be used toproduce a condensable vapor. At about 20° C., water, hexane,trimethlybenzene, toluene, xylenes, and isooctane have sufficiently highvapor pressures that they can be used as condensable vapors. In theadsorption branch of the isotherm, capillary condensation fills emptymicropore, mesopore, and much of the empty macropore volume with liquid.During desorption, micropores, mesopores, and macropores pores filledwith liquid are emptied. It is well known that there is a hysteresisbetween the adsorption and desorption branches of the isotherm. Detailedanalysis of the adsorption isotherm relies in part on the Kelvinequation which is well known to those skilled in the art. The detailedanalysis provides a measurement of the volume fraction of the mesoporesand macropores in the structured adsorbent and to some extent the sizedistribution of open mesopores and macropores.

Although the open pore volume for the contactor is determined by thetest procedure described above, scanning electron microscopy may be usedto further confirm the relative volume of mesopores and macropores inthe sample. When scanning electron microscopy is used the surface aswell as a cross section of the contactor should be imaged.

Open mesopore and macropore volume includes the volume fraction of allmesopores and macropores that are not filled with an optional blockingagent, and that are non-selective and thus are capable of being occupiedessentially by all components of the gas mixture. Non-limiting examplesof blocking agents that can be used in the practice of the presentinvention include polymers, microporous materials, solid hydrocarbons,and liquids that can fill the open mesoporous and macroporous spaces butstill allow molecules to transport into the micropores in the selectiveadsorbent. When the blocking agent is a polymer or liquid, it ispreferred that the molecular size of the blocking agent be large enoughso that is does not significantly invade micropores of the adsorbent,but not so large that it does not fill the mesopores and macropores.When solid blocking agents are used the particle size of the solid isgreater than any selective micropores in the adsorbent but smaller thanthe meso and macropores. As such the blocking agent can fit into themeso and macropores without significantly occluding or fillingmicropores which may be present in the adsorbent.

The blocking agent fills the open meso and macropores of the adsorbentto an extent that the volume fraction of the open meso and macropores ofthe adsorbent meets the aforementioned requirements. Non-limitingexamples of polymers that can be used as blocking agents includepolyimides, polysulfones, and silicone rubbers. Non-limiting examples ofliquids that can be used as blocking agents include amines, aromaticssuch as 1,3,5 trimethylbenzene and branched saturated hydrocarbons sucha heptamethylnonane as well as liquid hydrocarbons having carbon numbersin the about 5 to about 60 range. When a liquid blocking agent is usedit is advantageous to saturate, or nearly saturate, the feed gas withthe liquid blocking agent. Non-limiting examples of solid blockingagents include hydrocarbons such as waxes and those having carbonnumbers in the 10-1000 range. Non-limiting examples of microporousmaterials that can be used in the practice of the present inventioninclude microporous carbons and zeolites having pore sizes larger thanthose of the selective structured adsorbent of this invention. Anexample of an adsorbent formulated with a blocking agent is a silica oralumina bound zeolite layer having about 30% mesoporous and macroporousvolume in the interstices between the zeolite particles that is filledin with a liquid so that substantially all voids are filled with liquid(i.e., the total resulting macro and mesoporosity in the layer is lessthan about 20%). In some cases, the blocking agent forms a continuousnetwork and the adsorbent is a composite structure with the microporousmaterial embedded within the blocking agent. A non-limiting example ofsuch a structure is a zeolite/polymer composite where the polymer iscontinuous and the composite has less than about 20 vol % in openmesopores and macropores.

It is also possible to formulate the adsorbent using a mesoporousmaterial that fills the macropores to reduce the overall void, or open,volume. An example of such a structure would be an adsorbent havingabout 30 vol % of macropores that are filled in with a mesoporous solgel so that the resulting mesopore and macropore volume is less thanabout 20 vol %.

An example of a process where an adsorbent structure comprising ITQ-55can be used is a swing adsorption process. A swing adsorption processcan include an adsorption step followed by a desorption step to recoverthe adsorbed component. During the adsorption step, “heavy” componentsare selectively adsorbed and the weakly adsorbed (i.e., “light”)components pass through the bed to form the product gas. It is possibleto remove two or more contaminants simultaneously but for convenience,the component or components, that are to be removed by selectiveadsorption will be referred to in the singular and referred to as acontaminant or heavy component. In a swing adsorption process, thegaseous mixture is passed over a first adsorption bed in a first vesseland a light component enriched product stream emerges from the beddepleted in the contaminant, or heavy component, which remains sorbed inthe bed. After a predetermined time or, alternatively when abreak-through of the contaminant or heavy component is observed, theflow of the gaseous mixture is switched to a second adsorption bed in asecond vessel for the purification to continue. While the second bed isin adsorption service, the sorbed contaminant, or heavy component isremoved from the first adsorption bed by a reduction in pressure. Insome embodiments, the reduction in pressure is accompanied by a reverseflow of gas to assist in desorbing the heavy component. As the pressurein the vessels is reduced, the heavy component previously adsorbed inthe bed is progressively desorbed to a heavy component enriched productstream. When desorption is complete, the sorbent bed may be purged withan inert gas stream, e.g., nitrogen or a purified stream of process gas.Purging may also be facilitated by the use of a purge stream that ishigher in temperature than the process feedstream.

After breakthrough in the second bed and after the first bed has beenregenerated so that it is again ready for adsorption service, the flowof the gaseous mixture is switched back to the first bed, and the secondbed is regenerated. The total cycle time is the length of time from whenthe gaseous mixture is first conducted to the first bed in a first cycleto the time when the gaseous mixture is first conducted to the first bedin the immediately succeeding cycle, i.e., after a single regenerationof the first bed. The use of third, fourth, fifth, etc. vessels inaddition to the second vessel can serve to increase cycle time whenadsorption time is short but desorption time is long.

In some aspects, an RCPSA process can be used for separation. The totalcycle times of RCPSA may be less than about 30 seconds, preferably lessthan about 15 seconds, more preferably less than about 10 seconds, evenmore preferably less than about 5 seconds, and even more preferably lessthan about 1 second. Further, the rapid cycle pressure swing adsorptionunits can make use of substantially different sorbents, such as, but notlimited to, structured materials such as monoliths, laminates, andhollow fibers.

An adsorbent contactor may optionally contain a thermal mass (heattransfer) material to help control heating and cooling of the adsorbentof the contactor during both the adsorption step and desorption step ofa pressure swing adsorption process. Heating during adsorption is causedby the heat of adsorption of molecules entering the adsorbent. Theoptional thermal mass material also helps control cooling of thecontactor during the desorption step. The thermal mass can beincorporated into the flow channels of the contactor, incorporated intothe adsorbent itself, or incorporated as part of the wall of the flowchannels. When it is incorporated into the adsorbent, it can be a solidmaterial distributed throughout the adsorbent layer or it can beincluded as a layer within the adsorbent. When it is incorporated aspart of the wall of the flow channel, the adsorbent is deposited orformed onto the wall. Any suitable material can be used as the thermalmass material in the practice of the present invention. Non-limitingexamples of such materials include metals, ceramics, and polymers.Non-limiting examples of preferred metals include steel alloys, copper,and aluminum. Non-limiting examples of preferred ceramics includesilica, alumina, and zirconia. An example of a preferred polymer thatcan be used in the practice of the present invention is polyimide.Depending upon the degree to which the temperature rise is to be limitedduring the adsorption step, the amount of thermal mass material used canrange from about 0 to about 25 times the mass of the microporousadsorbent of the contactor. A preferred range for the amount of thermalmass in the contactor is from about 0 to 5 times the mass of themicroporous adsorbent of the contactor. A more preferred range for theamount of thermal mass material will be from about 0 to 2 times the massof the microporous adsorbent material, most preferably from about 0 to 1times the mass of the microporous material of the contactor.

The overall adsorption rate of the swing adsorption processes ischaracterized by the mass transfer rate from the flow channel into theadsorbent. It is desirable to have the mass transfer rate of the speciesbeing removed (i.e., the heavy component) high enough so that most ofthe volume of the adsorbent is utilized in the process. Since theadsorbent selectively removes the heavy component from the gas stream,inefficient use of the adsorbent layer can lower recovery of the lightcomponent and/or decrease the purity of the light product stream. Withuse of the adsorbent contactors described herein, it is possible toformulate an adsorbent with a low volume fraction of meso andmacroporous such that most of the volume of the adsorbent, which will bein the microporous range, is efficiently used in the adsorption anddesorption of the heavy component. One way of doing this is to have anadsorbent of substantially uniform thickness where the thickness of theadsorbent layer is set by the mass transfer coefficients of the heavycomponent and the time of the adsorption and desorption steps of theprocess. The thickness uniformity can be assessed from measurements ofthe thickness of the adsorbent or from the way in which it isfabricated. It is preferred that the uniformity of the adsorbent be suchthat the standard deviation of its thickness is less than about 25% ofthe average thickness. More preferably, the standard deviation of thethickness of the adsorbent is less than about 15% of the averagethickness. It is even more preferred that the standard deviation of theadsorbent thickness be less than about 5% of the average thickness.

Calculation of these mass transfer rate constants is well known to thosehaving ordinary skill in the art and may also be derived by those havingordinary skill in the art from standard testing data. D. M. Ruthven & C.Thaeron, Performance of a Parallel Passage Absorbent Contactor,Separation and Purification Technology 12 (1997) 43-60, which isincorporated herein by reference, clarifies many aspects of how the masstransfer is affected by the thickness of the adsorbent, channel gap andthe cycle time of the process. Also, U.S. Pat. No. 6,607,584 to Moreauet al., which is also incorporated by reference, describes the detailsfor calculating these transfer rates and associated coefficients for agiven adsorbent and the test standard compositions used for conventionalPSA.

FIG. 6 hereof is a representation of a parallel channel contactor in theform of a monolith formed directly from a microporous adsorbent plusbinder and containing a plurality of parallel flow channels. A widevariety of monolith shapes can be formed directly by extrusionprocesses. An example of a cylindrical monolith 1 is shown schematicallyin FIG. 6 hereof. The cylindrical monolith 1 contains a plurality ofparallel flow channels 3. These flow channels 3 can have channel gapsfrom about 5 to about 1,000 microns, preferably from about 50 to about250 microns, as long as all channels of a given contactor havesubstantially the same size channel gap. The channels can be formedhaving a variety of shapes including, but not limited to, round, square,triangular, and hexagonal. The space between the channels is occupied bythe adsorbent 5. As shown the channels 3 occupy about 25% of the volumeof the monolith and the adsorbent 5 occupies about 75% of the volume ofthe monolith. The adsorbent 5 can occupy from about 50% to about 98% ofthe volume of the monolith. The effective thickness of the adsorbent canbe defined from the volume fractions occupied by the adsorbent 5 andchannel structure as:Effective Thickness of Adsorbent=½ Channel Diameter*(Volume Fraction ofAdsorbent)/(Volume Fraction of Channels)

For the monolith of FIG. 6 hereof the effective thickness of theadsorbent will be about 1.5 times the diameter of the feed channel. Whenthe channel diameter is in a range from about 50 to about 250 microns itis preferred that the thickness of the adsorbent layer, in the casewherein the entire contactor is not comprised of the adsorbent, be in arange from about 25 to about 2,500 microns. For a 50 micron diameterchannel, the preferred range of thickness for the adsorbent layer isfrom about 25 to about 300 microns, more preferred range from about 50to about 250 microns. FIG. 7 is a cross-sectional view along thelongitudinal axis showing feed channels 3 extending through the lengthof the monolith with the walls of the flow channels formed entirely fromadsorbent 5 plus binder. A schematic diagram enlarging a small crosssection of the feed channels 3 and adsorbent layer 5 of FIG. 7 is shownin FIG. 8 hereof. The adsorbent layer is comprised of a microporousadsorbent, or polymeric, particles 7; solid particles (thermal mass) 9;that act as heat sinks, a blocking agent 13 and open mesopores andmicropores 11. As shown, the microporous adsorbent or polymericparticles 7 occupy about 60% of the volume of the adsorbent layer andthe particles of thermal mass 9 occupy about 5% of the volume. With thiscomposition, the voidage (flow channels) is about 55% of the volumeoccupied by the microporous adsorbent or polymeric particles. The volumeof the microporous adsorbent 5 or polymeric particles 7 can range fromabout 25% of the volume of the adsorbent layer to about 98% of thevolume of the adsorbent layer. In practice, the volume fraction of solidparticles 9 used to control heat will range from about 0% to about 75%,preferably about 5% to about 75%, and more preferably from about 10% toabout 60% of the volume of the adsorbent layer. A blocking agent 13fills the desired amount of space or voids left between particles sothat the volume fraction of open mesopores and macropores 11 in theadsorbent layer 5 is less than about 20%.

When the monolith is used in a gas separation process that relies on akinetic separation (predominantly diffusion controlled) it isadvantageous for the microporous adsorbent or polymeric particles 7 tobe substantially the same size. It is preferred that the standarddeviation of the volume of the individual microporous adsorbent orpolymeric particles 7 be less than 100% of the average particle volumefor kinetically controlled processes. In a more preferred embodiment thestandard deviation of the volume of the individual microporous adsorbentor polymeric particles 7 is less than 50% of the average particlevolume. The particle size distribution for zeolite adsorbents can becontrolled by the method used to synthesize the particles. It is alsopossible to separate pre-synthesized microporous adsorbent particles bysize using methods such as a gravitational settling column. It may alsobe advantageous to use uniformly sized microporous adsorbent orpolymeric particles in equilibrium controlled separations.

There are several ways that monoliths can be formed directly from astructured microporous adsorbent. For example, when the microporousadsorbent is a zeolite, the monolith can be prepared by extruding anaqueous mixture containing effective amounts of a solid binder, zeoliteand adsorbent, solid heat control particles, and polymer. The solidbinder can be colloidal sized silica or alumina that is used to bind thezeolite and solid heat control particles together. The effective amountof solid binder will typically range from about 0.5 to about 50% of thevolume of the zeolite and solid heat control particles used in themixture. If desired, silica binder materials can be converted in a postprocessing step to zeolites using hydrothermal synthesis techniques and,as such, they are not always present in a finished monolith. A polymeris optionally added to the mixture for rheology control and to givegreen extrudate strength. The extruded monolith is cured by firing it ina kiln where the water evaporates and the polymer burns away, therebyresulting in a monolith of desired composition. After curing themonolith, the adsorbent layer 5 will have about 20 to about 40 vol. %mesopores and macropores. A predetermined amount of these pores can befilled with a blocking agent 13, as previously discussed, in asubsequent step such as by vacuum impregnation.

Another method by which a monolith can be formed directly from amicroporous adsorbent is by extruding a polymer and microporousadsorbent mixture. Preferred microporous adsorbents for use in extrusionprocess are carbon molecular sieves and zeolites. Non-limiting examplesof polymers suitable for the extrusion process include epoxies,thermoplastics, and curable polymers such as silicone rubbers that canbe extruded without an added solvent. When these polymers are used inthe extrusion process, the resulting product will preferably have a lowvolume fraction of mesopores and macropores in the adsorbent layer.

FIG. 9 hereof is a representation of a parallel channel contactor 101 inthe form of a coated monolith where an adsorbent layer is coated ontothe walls of the flow channels of a preformed monolith. For the parallelchannel contactors of FIG. 9, an extrusion process is used to form amonolith from a suitable non-adsorbent solid material, preferably ametal such as steel, a ceramic such as cordierite, or a carbon material.By the term “non-adsorbent solid material” we mean a solid material thatis not to be used as the selective adsorbent for the parallel channelcontactor. An effective amount and thickness of a ceramic or metallicglaze, or sol gel coating, 119 is preferably applied to effectively sealthe channel walls of the monolith. Such glazes can be applied by slurrycoating the channel walls, by any suitable conventional means, followedby firing the monolith in a kiln.

Another approach is to apply a sol gel to the channel walls followed byfiring under conditions that densify the coating. It is also possible touse vacuum and pressure impregnation techniques to apply the glaze orsol gel to the channel walls. In such a case, the glaze or sol gel willpenetrate into the pore structure of the monolith 117. In all cases, theglaze seals the wall of the channel such that gas flowing through thechannel is not readily transmitted into the body of the monolith. Anadsorbent layer 105 is then uniformly applied onto the sealed walls ofthe channels. The adsorbent layer 105 reduces the opening, or bore, ofthe channels, thus the flow channel 103 used in swing adsorptionprocesses is the open channel left inside of the coating. These flowchannels 103 can have channel gaps as previously defined. The adsorbentlayer 105 can be applied as a coating, or layer, on the walls of theflow channels by any suitable method. Non-limiting examples of suchmethods include fluid phase coating techniques, such as slurry coatingand slip coating. The coating solutions can include at least themicroporous adsorbent or polymeric particles, a viscosifying agent suchas polyvinyl alcohol, heat transfer (thermal mass) solids, andoptionally a binder. The heat transfer solid may not be needed becausethe body of the monolith 101 can act to as its own heat transfer solidby storing and releasing heat in the different steps of the separationprocess cycle. In such a case, the heat diffuses through the adsorbentlayer 105 and into the body of the monolith 101. If a viscosifyingagent, such as polyvinyl alcohol, is used it is usually burns away whenthe coating is cured in a kiln. It can be advantageous to employ abinder such as colloidal silica or alumina to increase the mechanicalstrength of the fired coating. Mesopores or macropores will typicallyoccupy from about 20 to about 40% of the volume of the cured coating. Aneffective amount of blocking agent is applied to complete the adsorbentlayer for use. By effective amount of blocking agent we mean that amountneeded to occupy enough of the mesopores and macropores such that theresulting coating contains less than about 20% of its pore volume inopen mesopores and macropores.

If a hydrothermal film formation method is employed, the coatingtechniques used can be very similar to the way in which zeolitemembranes are prepared. An example of a method for growing a zeolitelayer is taught in U.S. Pat. No. 7,049,259, which is incorporated hereinby reference. Zeolite layers grown by hydrothermal synthesis on supportsoften have cracks and grain boundaries that are mesopore and macroporein size. The volume of these pores is often less than about 10 volume %of the film thickness and there is often a characteristic distance, orgap, between cracks. Thus, as-grown films can often be used directly asan adsorbent layer without the need for a blocking agent.

FIG. 10 hereof is a representation of a parallel channel contactor ofthe present invention in which the parallel channels are formed fromlaminated sheets containing adsorbent material. Laminates, laminates ofsheets, or laminates of corrugated sheets can be used in PSA RCPSA, PPSAor RCPPSA processes. Laminates of sheets are known in the art and aredisclosed in U.S. patent applications US20060169142 Al and U.S. Pat. No.7,094,275 B2 which are incorporated herein by reference. When theadsorbent is coated onto a geometric structure or components of ageometric structure that are laminated together, the adsorbent can beapplied using any suitable liquid phase coating techniques. Non-limitingexamples of liquid phase coating techniques that can be used in thepractice of the present invention include slurry coating, dip coating,slip coating, spin coating, hydrothermal film formation and hydrothermalgrowth. When the geometric structure is formed from a laminate, thelaminate can be formed from any material to which the adsorbent of thepresent invention can be coated. The coating can be done before or afterthe material is laminated. In all these cases the adsorbent is coatedonto a material that is used for the geometric shape of the contactor.Non-limiting examples of such materials include glass fibers, milledglass fiber, glass fiber cloth, fiber glass, fiber glass scrim, ceramicfibers, metallic woven wire mesh, expanded metal, embossed metal,surface-treated materials, including surface-treated metals, metal foil,metal mesh, carbon-fiber, cellulosic materials, polymeric materials,hollow fibers, metal foils, heat exchange surfaces, and combinations ofthese materials. Coated supports typically have two major opposingsurfaces, and one or both of these surfaces can be coated with theadsorbent material. When the coated support is comprised of hollowfibers, the coating extends around the circumference of the fiber.Further support sheets may be individual, presized sheets, or they maybe made of a continuous sheet of material. The thickness of thesubstrate, plus applied adsorbent or other materials (such as desiccant,catalyst, etc.), typically ranges from about 10 micrometers to about2000 micrometers, more typically from about 150 micrometers to about 300micrometers.

FIG. 10 hereof illustrates an exploded view of an embodiment of thepresent invention wherein a microporous adsorbent film 505 is on each ofboth faces of flat metal foils 509, which is preferably fabricated froma corrosion resistant metal such as stainless steel. The separate metalfoils 509 with the adsorbent films 505 are fabricated to form a parallelchannel contactor 501. Spacers of appropriate size may be placed betweenthe metal foils during contactor fabrication so that the channel gap 503is of a predetermined size. Preferably about half of the volume of thefeed channels 503 are filled with a spacer that keeps the sheetssubstantially evenly spaced apart.

Metallic mesh supports can provide desirable thermal properties of highheat capacity and conductivity which “isothermalize” a PSA, RCPSA, PPSAor RCPPSA cycle to reduce temperature variations that degrade theprocess when conducted under more adiabatic conditions. Also, metalfoils are manufactured with highly accurate thickness dimensionalcontrol. The metal foil may be composed of, without limitation,aluminum, steel, nickel, stainless steel or alloys thereof. Hence thereis a need for a method to coat metal foils with a thin adsorbent layerof accurately controlled thickness, with necessary good adhesion. Onemethod for doing this is by hydrothermal synthesis. Coating proceduresused can be very similar to the way in which zeolite membranes areprepared as discussed above. Zeolite layers grown by hydrothermalsynthesis on supports often have cracks which are mesopores andmicropores. The volume of these pores is often less than about 10 volume% of the film thickness and there is often a characteristic distancebetween cracks. Another method of coating a metal foil is with thickfilm coating is slip casting, or doctor blading. An aqueous slurry ofprefabricated zeolite particles, binder (for example colloidal silica oralumina), viscosifying agent such as a polymer like polyvinyl alcohol iscast for example onto a metal foil and fired to remove the polymer andcure the binder and zeolite. The product, after firing, is then a boundzeolite film on a metal foil typically containing about 30 to about 40volume % voids. To make a suitable adsorbent layer, the voids are filledin a subsequent step by coating the bound zeolite film with a polymer orby introducing a liquid into the voids of the bound zeolite film. Thefinal product, after filling the voids with a polymer or liquid, will bean adsorbent layer having the low mesoporosity and microporosityrequirements of the present invention.

Another method for coating metal foils with prefabricated zeolitecrystals, or microporous particles, is electrophoretic deposition (EPD).EPD is a technique for applying high quality coatings of uniformthickness to metal substrates. The method can be used to apply organicand inorganic particulate coatings on electrically conductivesubstrates. Slurry compositions containing prefabricated zeolites, ormicroporous particles, may be electrophoretically applied to a rigidsupport material, such as by using the method described in Bowie Keeferet al.'s prior Canadian patent application No. 2,306,311, entitled“Adsorbent Laminate Structure,” which is incorporated herein byreference.

Some contactor geometric shapes will require that the adsorbent beapplied to the channel surface in a layer using a colloidal bindermaterial or that an entire geometric shape be comprised of the adsorbentplus colloidal binder and containing a plurality of parallel channels.When a colloidal binder is used, the selection of the colloidal materialdepends on the particular adsorbent used. Colloidal materials capable offunctioning as a binder and/or which form a gel are preferred. Suchcolloidal materials include, without limitation, colloidal silica-basedbinders, colloidal alumina, colloidal zirconia, and mixtures ofcolloidal materials. “Colloidal silica” refers to a stable dispersion ofdiscrete amorphous silicon dioxide particles having a particle sizeranging from about 1 to about 100 nanometers. Suitable colloidal silicamaterials also can be surface modified, such as by surface modificationwith alumina. Another type of colloidal binder suitable for use hereininclude clay materials, such as palygorskite (also known asattapulgite), which are hydrated magnesium aluminum silicates. Also,inorganic binders may be inert; however, certain inorganic binders, suchas clays, used with zeolite adsorbents may be converted in-situ fromkaolin binders to zeolite so that the zeolite is self-bound with minimalinert material. In these bound structures, the voids between thecolloidal particles form mesopores and the voids between the adsorbentparticles form mesopores and/or macropores. A blocking agent can beapplied to fill the majority of the mesoporosity and microporosity inthese bound layers so that the adsorbent meets the open pore volumerequirement of this invention. Organic binders used to bind activatedcarbon particulates in laminated structures may be pyrolyzed to form auseful carbonaceous adsorbent.

In some aspects, it would be valuable in the industry to enable theseparation of certain contaminants from a natural gas feedstream. Somecontaminants that are particularly of interest for removal are water(H₂O), nitrogen (N₂) and carbon dioxide (CO₂). The term “natural gas” or“natural gas feedstream” as used herein is meant to cover natural gas asextracted at the well head, natural gas which has been furtherprocessed, as well as natural gas for pipeline, industrial, commercialor residential use.

Of particular interest herein, is the use of the ITQ-55 material forremoving contaminants from natural gas at wellheads (or after someamount of pre-processing) for further processing of the natural gas tomeet the necessary specifications for putting the natural gas into apipeline or for its intermediate or final industrial, commercial, orresidential use. Of particular interest is the ability to remove one ormore of these contaminants (H₂O, N₂, and/or CO₂) at the relatively highnatural gas well processing pressure conditions. The removal of H₂O fromnatural gas (i.e., in particular the methane and higher molecular weighthydrocarbon components of the natural gas) is important to the abilityto further process the natural gas in processes where water isdetrimental to the process (e.g., cryogenic separation of thehydrocarbons in the natural gas stream), as well as to meet certainspecifications on the composition of the natural gas. The removal of N₂from natural gas (i.e., in particular the methane and higher molecularweight hydrocarbon components of the natural gas) is important to removethis inert gas prior to further processing of the natural gas inprocesses which in turn substantially reduces overall processingfacility capacity size requirements, as well as to meet certainspecifications on the composition of the natural gas. The removal of CO₂from natural gas (i.e., in particular the methane and higher molecularweight hydrocarbon components of the natural gas) is important to removethis inert gas prior to further processing of the natural gas inprocesses which reduces overall processing facility capacity sizerequirements, as well as to meet certain specifications on thecomposition of the natural gas.

It is of substantial benefit if the removal of these contaminants can bedone at the relatively high pressures near the natural gas wellhead, asnatural gas is usually produced at pressures ranging from 1,500 to 7,000psi (10.3 MPa-48.3 MPa); and wherein the natural gas feedstream can befed to the separations processes at over 300 psia (2.1 MPa), 500 psia(3.4 MPa), or even 1000 psia (6.9 MPa), such as up to about 2500 psia(about 17 Mpa) or more. There are few, if any, materials that canoperate reliably and effectively to separate these contaminants frommethane and other higher molecular weight hydrocarbons under PSA, PPSA,RCPSA, RCPPSA, or TSA (or combined cycle processes such as PSA/TSA,PPSA/TSA, RCPSA/TSA, and RCPPSA/TSA, wherein steps from each process arecombined in the overall cycle) cycle conditions at these high pressureconditions. Some of the benefits of being to perform these separationsat these high pressures include smaller equipment size (due to thesmaller gas volume at high pressures) and the ability to use the productstreams from these separations processes in further processing orpipeline transportation without the need for, or the reduced need for,equipment and energy required to repressurize the resulting separationsproduct stream(s) for such further use.

In embodiments herein, the ITQ-55 material can be used in PSA, PPSA,RCPSA, RCPPSA, TSA or combined cycle conditions at natural gas feedpressures in the range of about 5 to about 5,000 psia (about 0.03 MPa toabout 35 MPa), about 50 to about 3,000 psia (about 0.34 MPa to about 21MPa), about 100 to about 2,000 psia (about 0.69 MPa to about 14 MPa),about 250 to about 1,500 psia (about 1.7 MPa to about 10 MPa), over 50psia (0.34 MPa), over 250 psia (1.7 MPa), over 500 psia (3.4 MPa), orover 1000 psia (6.9 MPa). In embodiments, operating natural gas feedtemperatures may be from about 0 to about 750° F. (about −18° C. toabout 399° C.), about 100 to about 600° F. (about 38° C. to about 316°C.), or about 150 to about 500° F. (about 66° C. to about 260° C.).

As can be seen from FIG. 17, and as described elsewhere herein, theITQ-55 material shows an exponentially increasing capacity for water athigher pressures, while other materials considered for this use (i.e.,zeolite 5A) appear to have only very small increases in water capacityat higher pressures. As is discussed elsewhere herein, ITQ-55 has a veryhigh adsorption affinity for each of these contaminants (H₂O, N₂, andCO₂) while at the same time exhibiting very low adsorption of methane(CH₄) or higher molecular weight hydrocarbons. The ITQ-55 material canbe used in these associated swing processes in either an equilibrium orkinetic separations regime. In these processes, ITQ-55 in itssubstantially pure silica may be used, or the ITQ-55 utilized maypossess a Si/Al ratio from about 10:1 to about 1000:1, or about 50:1 toabout 500:1.

In some embodiments for processing a natural gas feedstream, the PSA,PPSA, RCPSA, RCPPSA, TSA or combined cycle conditions described hereinmay be operated with regimes wherein the Selectivity (as defined prioras U_(A)/U_(B); where U_(A)>U_(B)) is greater than about 5, greater thanabout 10, greater than about 50, or even greater than about 100, and Ais H₂O and B is methane and higher molecular weight hydrocarbons. Inother embodiments for processing a natural gas feedstream, the PSA,PPSA, RCPSA, RCPPSA, TSA or combined cycle conditions described hereinmay be operated with regimes wherein the Selectivity (as defined prioras U_(A)/U_(B); where U_(A)>U_(B)) is greater than about 5, is greaterthan about 10, greater than about 50, or even greater than about 100,and A is N₂ and B is methane and higher molecular weight hydrocarbons.In still other embodiments for processing a natural gas feedstream, thePSA, PPSA, RCPSA, RCPPSA, TSA or combined cycle conditions describedherein may be operated with regimes wherein the Selectivity (as definedprior as U_(A)/U_(B); where U_(A)>U_(B)) is greater than about 5, isgreater than about 10, greater than about 50, or even greater than about100, and A is CO₂ and B is methane and higher molecular weighthydrocarbons.

Membrane Separations

In some aspects, the zeolite ITQ-55 can be used as part of a membrane.An example of a membrane can be a layer comprising a supported inorganiclayer comprising contiguous particles of a crystalline molecular sieve.Another example of a membrane can be a self-supported layer of zeolitecrystal particles. The particles having a mean particle size within therange of from 20 nm to 1 μm. In one type of aspect, the mean particlesize can optionally be within the range of from 20 to 500 nm, preferablyit is within the range of from 20 to 300 nm and most preferably withinthe range of from 20 to 200 nm. Alternatively, the mean particle sizecan advantageously be such that at least 5% of the unit cells of thecrystal are at the crystal surface. Optionally, the particles can have amean particle size within the range of from 20 to 200 nm.

In such an aspect, the layer can comprises molecular sieve particlesoptionally coated with skin of a different material; these areidentifiable as individual particles (although they may be intergrown asindicated below) by electron microscopy. The layer, at least afteractivation, is mechanically cohesive and rigid. Within the intersticesbetween the particles in this rigid layer, there may exist a plethora ofnon-molecular sieve pores, which may be open, or partially open, topermit passage of material through or within the layer, or may becompletely sealed, permitting passage through the layer only through thepores in the particles. Advantageously, the particle size distributionis such that 95% of the particles have a size within ±33% of the mean,preferably 95% are within ±15% of the mean, preferably +10% of the meanand most preferably 95% are within ±7.5% of the mean.

It will be understood that the particle size of the molecular sievematerial forming the layer may vary continuously or stepwise withdistance from the support. In such a case, the requirement foruniformity is met if the particle size distribution is within thedefined limit at one given distance from the support, althoughadvantageously the particle size distribution will be within the definedlimit at each given distance from the support. The use of molecularsieve crystals of small particle size and preferably of homogeneous sizedistribution facilitates the manufacture of a three-dimensionalstructure which may if desired be thin but which is still of controlledthickness.

In some aspects, the particles of ITQ-55 can be contiguous, i.e.,substantially every particle is in contact with one or more of itsneighbors as evidenced by electron microscopy preferably high resolutionmicroscopy, although not necessarily in contact with all its closestneighbors. Such contact may be such in some embodiments that neighboringcrystal particles are intergrown, provided they retain their identity asindividual crystalline particles. Advantageously, the resulting threedimensional structure is grain-supported, rather than matrix-supported,in the embodiments where the layer does not consist essentially of thecrystalline molecular sieve particles. In a preferred embodiment, theparticles in the layer are closely packed.

A layer may optionally be constructed to contain passageways between theparticles that provide a non-molecular sieve pore structure through orinto the layer. Such a layer may consist essentially of the particles ormay contain another component, which may be loosely termed a matrixwhich, while surrounding the particles, does not so completely orclosely do so that all pathways round the particles are closed.Alternatively, the layer may be constructed so that a matrix presentcompletely closes such pathways, with the result that the only paththrough or into the layer is through the particles themselves. It willbe understood that references herein to the support of a layer includeboth continuous and discontinuous supports.

References to particle size are throughout this specification to thelongest dimension of the particle and particle sizes are as measured bydirect imaging with electron microscopy. Particle size distribution maybe determined by inspection of scanning or transmission electronmicrograph images preferably on lattice images, and analyzing anappropriately sized population of particles for particle size.

A supported layer according to the invention may be manufactured in anumber of different ways. One option can be making a layer by depositionon a support from a colloidal zeolite suspension obtainable by preparingan aqueous synthesis mixture comprising a source of silica and anorganic structure directing agent in a proportion sufficient to effectsubstantially complete dissolution of the silica source in the mixtureat the boiling temperature of the mixture, and crystallization from thesynthesis mixture. The synthesis mixture will contain, in addition, asource of the other component or components, if any, in the zeolite. Inother aspects, one or more of the techniques described above forformation of an adsorbent structure can also be suitable for formationof a membrane structure.

The thickness of the molecular sieve layer can be, for example, withinthe range of 0.1 to 20 μm, or 0.1 to 15 μm, or from 0.1 to 2 μm.Advantageously, the thickness of the layer and the particle size of themolecular sieve are such that the layer thickness is at least twice theparticle size, resulting in a layer several particles thick rather thana monolayer of particles. Advantageously, the layer is substantiallyfree of pinholes, i.e., substantially free from apertures of greatestdimension greater than 0.1 μm. Advantageously, at most 0.1% andpreferably at most 0.0001% of the surface area is occupied by suchapertures.

The layer support may be either non-porous or, preferably, porous, andmay be continuous or particulate. As examples of non-porous supportsthere may be mentioned glass, fused quartz, and silica, silicon, denseceramic, for example, clay, and metals. As examples of porous supports,there may be mentioned porous glass, porous carbon, porous ceramics,sintered porous metals, e.g., steel or nickel (which have pore sizestypically within the range of 0.2 to 15 μm), and, especially, aninorganic oxide, e.g., alpha-alumina, titania, an alumina/zirconiamixture, or Cordierite. At the surface in contact with the layer, thesupport may have pores of dimensions up to 50 times the layer thickness,but preferably the pore dimensions are comparable to the layerthickness.

Still another option for forming the membrane layer can be to have ahybrid or composite layer. An example of a hybrid membrane layer can beparticles of zeolite ITQ-55 mixed with polymer(s) and spun as hollowfibers. Optionally, such fibers can be thermally converted tocarbonaceous materials to form a layer composed of ITQ-55 and carboncomposite fibers. As an example, hollow fiber membranes can be producedthrough a hollow fiber spinning process. One or more polymer solutionscan be extruded with bore fluid through an annular die into an aqueousquench bath. Optionally, two or more polymer solutions can beco-extruded to form a composite fiber. At least one of the polymersolutions can also include ITQ-55 crystal particles, so that the ITQ-55is incorporated into the hollow fiber structure. When the nascent fiberenters an aqueous quench bath, solvents diffuse from fibers into thequench bath while water from the quench bath diffuses into the fibers,which causes phase separation to occur. Open porous substructures can beformed during this phase separation process. A simple subsequentstandard process to prepare hollow fiber modules, as is known in theindustry, can then be used.

The layer may, and for many uses advantageously does, consistessentially of the molecular sieve material, or it may be a composite ofthe molecular sieve material and intercalating material which is alsoinorganic. The intercalating material may be the material of thesupport. If the layer is a composite it may, as indicated above, containmacropores and/or micropores, bounded by molecular sieve portions, byportions of intercalating material, or by both molecular sieve andintercalating material. The material may be applied to the supportsimultaneously with or after deposition of the molecular sieve, and maybe applied, for example, by a sol-gel process followed by thermalcuring. Suitable materials include, for example, inorganic oxides, e.g.,silica, alumina, and titania. The intercalating material isadvantageously present in sufficiently low a proportion of the totalmaterial of the layer that the molecular sieve crystals remaincontiguous.

In another example of a process for the manufacture of a layercomprising a crystalline molecular sieve on a porous support, the layercan be formed by pre-treating the porous support to form at a surfacethereof a barrier layer, and applying to the support a reaction mixturecomprising a colloidal suspension of molecular sieve crystals, having amean particle size of at most 100 nm and advantageously a particle sizedistribution such that at least 95% of the particles have a size within±15%, preferably ±10%, more preferably within ±7.5%, of the mean,colloidal silica and optionally an organic structure directing agent, toform a supported molecular sieve layer, and if desired or requiredactivating the resulting layer. Activation removes the template and canbe achieved by calcination, ozone treatment, plasma treatment orchemical extraction such as acid extraction. The invention also providesa supported layer formed by the process.

The barrier layer functions to prevent the water in the aqueous reactionmixture from preferentially entering the pores of the support to anextent such that the silica and zeolite particles form a thick gel layeron the support. The barrier layer may be temporary or permanent. As atemporary layer, there may be mentioned an impregnating fluid that iscapable of being retained in the pores during application of thereaction mixture, and readily removed after such application and anysubsequent treatment.

Spin coating can be still another advantageous technique for applyingthe reaction mixture to the support according to this and other aspectsof the invention. The impregnating fluid should accordingly be one thatwill be retained in the pores during spinning if that technique is used;accordingly the rate of rotation, pore size, and physical properties ofthe fluid need to be taken into account in choosing the fluid. The fluidshould also be compatible with the reaction mixture, for example if thereaction mixture is polar, the barrier fluid should also be polar. Asthe reaction mixture is advantageously an aqueous reaction mixture,water is advantageously used as the barrier layer. To improvepenetration, the fluid barrier may be applied at reduced pressure orelevated temperature. If spin-coating is used, the support treated withthe barrier fluid is advantageously spun for a time and at a rate thatwill remove excess surface fluid, but not remove fluid from the pores.Premature evaporation of fluid from the outermost pores during treatmentmay be prevented by providing an atmosphere saturated with the liquidvapor.

During spin-coating, the viscosity of the reaction mixture and the spinrate can control coating thickness. The mixture is advantageously firstcontacted with the stationary support, then after a short contact timethe support is spun at the desired rate. After spinning, the silica isadvantageously aged by retaining the supported layer in a high humidityenvironment, and subsequently dried, advantageously first at roomtemperature and then in an oven.

As still another option, there is provided a process for the manufactureof a layer comprising a crystalline molecular sieve on a porous supportwhich comprises applying to the support by dip-coating a colloidalsuspension of molecular sieve crystals, having a mean particle size ofat most 100 nm and advantageously a particle size distribution such thatat least 95% of the particles have a size within ±15%, preferably ±10%,more preferably ±7.5%, of the mean, drying the resulting gel on thesupport and if desired or required activating the resulting layer. Stillanother option can include synthesizing molecular sieve crystals in situon a support.

Storage Applications

In various aspects, an adsorbent structure as described above can alsobe used for storage of fluids. The initial adsorption of a fluid orfluid component into an adsorbent structure can be performed in anyconvenient manner, such as according to the adsorption processesdescribed above. Optionally, the adsorption of fluids for storage can beperformed using an input gas substantially composed of a singlecomponent, as opposed to also performing a separation during adsorption.

In some aspects, after a fluid is adsorbed in an adsorbent structure,the adsorbent structure can be maintained at a temperature and/orpressure similar to the conditions used during the adsorption. In otheraspects, at least one of the temperature and/or the pressure can bemodified to assist with maintaining the fluid in the adsorbentstructure. For example, after adsorbing a fluid at a first temperature,the temperature of the adsorbent structure can be reduced to assist withmaintaining the fluid within the adsorbent structure.

The conditions for maintaining an adsorbed fluid within the adsorbentstructure can depend in part on the nature of the adsorbed component.For example, hydrogen can be readily adsorbed by ITQ-55, but hydrogencan likely also desorb from ITQ-55 at a wide range of temperatures. Inorder to maintain a desired stored amount of hydrogen within anadsorbent structure, an exterior pressure of hydrogen may be needed, sothat the hydrogen outside of the adsorbent structure is in equilibriumwith the hydrogen inside of the adsorbent structure. This situation canbe in contrast to storage of methane, ethylene, methanol, ethane, oranother hydrocarbon/organic compound in an adsorbent structure.Hydrocarbons and organic compounds can have a limited ability to enterinto and/or diffuse within the pore structure of ITQ-55 at lowertemperatures and/or pressures. As a result, an amount of hydrocarbonand/or organic compound can be stored within an adsorbent structurebased on ITQ-55 without having a corresponding equilibrium amount of thestored component outside of the adsorbent structure.

During an initial adsorption step, a fluid component can be adsorbedinto the adsorbent structure. The conditions during adsorption caninclude, for example, a) a temperature of at least about 325 K, or atleast about 375 K, or at least about 425 K, or at least about 475 K; b)a pressure of at least about 100 bar (10 MPaa), or at least about 300bar (30 MPaa), or at least about 500 bar (50 MPaa), or at least about700 bar (70 MPaa); or c) a combination thereof. Without being bound byany particular theory, the elevated temperature and/or pressure canallow for introduction of an elevated loading of an organic componentinto the adsorbent structure.

After loading of the adsorbent structure, the temperature and/orpressure can be reduced. In aspects where loading of the adsorbentstructure is performed at an elevated pressure, the pressure can bereduced to about 100 bar (10 MPaa) or less, or about 10 bar (1 MPaa) orless, or about 2 bar (0.2 MPaa) or less, or about 1 bar (0.1 MPaa) orless. In aspects where loading of the adsorbent structure is performedat an elevated temperature, the temperature can be reduced to about 325K or less, or about 300 K or less, or about 275 K or less, or about 250K or less, or about 225 K or less, or about 200 K or less. In aspectswhere both the temperature and pressure are elevated during loading, thetemperature can optionally be reduced first, and then the pressure canbe reduced. After reducing the temperature and/or pressure, somedesorption of the adsorbed component can occur. However, based on thereduced temperature and/or pressure conditions, a portion of thecomponent can remain kinetically trapped within the adsorbent structure.This can allow the adsorbent structure to retain an amount of the fluidcomponent within the adsorbent structure, even though the atmosphereoutside of the adsorbent may no longer contain the adsorbed component.The loading retained within the adsorbent can correspond to a percentageof the loading that was achieved during adsorption, such as at leastabout 10 wt % of the loading during adsorption, or at least about 20 wt%, or at least about 30 wt %, or at least about 40 wt %, or at leastabout 50 wt %, or at least about 60 wt %. The adsorbent structure canthen optionally be transported under the reduced temperature and/orpressure conditions.

After storage for a desired amount of time, the temperature can beincreased to allow the adsorbed component to exit from the adsorbentstructure. This can allow the adsorbed component, corresponding to afuel and/or potential reactant, to be stored and optionally transportedunder less severe conditions. In other words, the temperature and/orpressure required for storage of the adsorbed component in the adsorbentstructure can be reduced relative to the conditions required for storingthe adsorbed component in the absence of the adsorbent structure. Theamount of storage time can be any convenient amount of time, such as atleast a day, or at least a month, and up to a year or more.

Catalysis Process and Method of Use

In addition to separations, zeolite ITQ-55 can also be suitable for useas a catalyst for a variety of reactions. In some aspects, ITQ-55 can besuitable for catalysis of reactions that can generally be catalyzed byzeolites having an 8-member ring as the largest ring size. For example,the selective catalytic reduction of nitrogen oxides, optionally in thepresence of ammonia, is a reaction that can be catalyzed using 8-memberring zeolites.

Other examples of suitable catalytic uses of zeolite ITQ-55 canpotentially include, but are not limited to, (a) hydrocracking of heavypetroleum residual feedstocks, cyclic stocks and other hydrocrackatecharge stocks, normally in the presence of a hydrogenation component isselected from Groups 6 and 8 to 10 of the Periodic Table of Elements;(b) dewaxing, including isomerization dewaxing, to selectively removestraight chain paraffins from hydrocarbon feedstocks typically boilingabove 177° C., including raffinates and lubricating oil basestocks; (c)catalytic cracking of hydrocarbon feedstocks, such as naphthas, gas oilsand residual oils, normally in the presence of a large pore crackingcatalyst, such as zeolite Y; (d) oligomerization of straight andbranched chain olefins having from about 2 to 21, preferably 2 to 5carbon atoms, to produce medium to heavy olefins which are useful forboth fuels, i.e., gasoline or a gasoline blending stock, and chemicals;(e) isomerization of olefins, particularly olefins having 4 to 6 carbonatoms, and especially normal butene to produce iso-olefins; (f)upgrading of lower alkanes, such as methane, to higher hydrocarbons,such as ethylene and benzene; (g) disproportionation of alkylaromatichydrocarbons, such as toluene, to produce dialkylaromatic hydrocarbons,such as xylenes; (h) alkylation of aromatic hydrocarbons, such asbenzene, with olefins, such as ethylene and propylene, to produceethylbenzene and cumene; (i) isomerization of dialkylaromatichydrocarbons, such as xylenes, (j) catalytic reduction of nitrogenoxides, (k) synthesis of monoalkylamines and dialkylamines, (l)conversion of methanol to dimethyl ether, (m) conversion of methanol(and/or other oxygenates) to olefins, and (n) conversion of methanol(and/or other oxygenates) to aromatics.

For at least some of the above reaction types, effective catalysis ofthe reaction by zeolite ITQ-55 can involve at least partial entry of oneor more reactants into the pore structure of the zeolite. The porestructure of zeolite ITQ-55 includes 8-member ring channels. The8-member ring channels include a minimum pore channel size in the porenetwork of 5.9 Angstroms×2.1 Angstroms at ambient temperature. Thisminimum pore channel size can limit the types of compounds that caneffectively enter and/or pass through the pore network. However, the8-member ring that provides the minimum size is also believed to haveflexibility. This flexibility can allow the 8-member ring to deform,such as due to thermal fluctuations and/or due to fluctuations inducedat elevated pressures, which can lead to a potential temporary increasein the size of the pore channel. Without being bound by any particulartheory, it is believed that the flexibility of the 8-member ringdefining the size of the pore channel can allow for additional tuning ofcatalysis of various reactions based on temperature and/or pressure.

Additionally or alternately, the particle size of ITQ-55 crystals usedin an adsorbent structure or membrane structure can have an impact onthe ability of the adsorbent structure or membrane structure to performcatalysis. As one example, the particle size of the ITQ-55 crystals canhave an influence on the amount of “dead space” that is present at thesurface and/or within the interior of an adsorbent structure or membranestructure. Mathematically, the packing density of a collection of hardspheres of similar size is dependent on the radius of the spheres. For acollection of hard spheres, the larger the average radius, the largerthe size of the spaces or gaps between the hard spheres. Without beingbound by any particular theory, it is believed that for a collection ofITQ-55 crystals of similar size, the size of the voids or dead spacescreated after close packing of crystals can be related to the averageparticle size. Having a smaller particle size can reduce such deadspace, thus providing an increased pore surface area for accepting fluidcomponents for catalysis.

Additionally or alternately, the composition of ITQ-55 crystals used canhave an impact on the catalytic properties of a catalyst. In someaspects, ITQ-55 can be synthesized to have a framework structurecomposed of primarily silicon and oxygen. In other aspects, a portion ofthe framework atoms in the ITQ-55 structure can be replaced with otherelements. For example, a portion of the silicon in the frameworkstructure can be replaced with atoms from a different group in theperiodic table, such as Al, P, and/or B. In an aspect, a portion of thesilicon in the framework structure can be replaced with Al. As anotherexample, a portion of the silicon in the framework can be replaced withatoms from a different row of the periodic table, such as Ge or P. Suchcomposition variations can modify the size of the pores within thecrystal structure and/or modify the affinity of the ITQ-55 relative toone or more potential reactants, which can influence the ability tocatalyze a reaction. Additionally or alternately, such compositionvariations can also alter the properties of the ITQ-55 crystals, such asthe acidity of the crystals, which can also influence catalyticactivity.

When used as a catalyst, the ITQ-55 crystals can be incorporated into acatalyst by any convenient method. In some aspects, extruded catalystparticles can be a convenient catalyst form. Such extruded catalystparticles can include the zeolite crystals as well as an optionalbinder. Optionally, catalytic metals can be added to such catalystparticles, such as by impregnation. For catalyst particles that includean optional binder, the optional binder can be present in any convenientamount, such as from about 10 wt % to about 90 wt %, more typically fromabout 30 wt % to about 70 wt %. Suitable binders can include, but arenot limited to, metal oxides such as silica, alumina, silica-alumina,zirconia, titania, and combinations thereof. Suitable catalytic metalscan include, but are not limited to, transition metals. Examples ofsuitable transition metals include Group VI metals (Mo, W), Group VIIImetals (Co, Ni, Pt, Pd, Fe, Ir), and combinations thereof. Suchcatalytic metals can be present in an amount of about 0.1 wt % to about40 wt % relative to the weight of the catalyst particles. Additionallyor alternately, in some aspects, catalyst particles (for example,supported catalyst particles) that include ITQ-55 crystals can furtherinclude one or more additional zeolites, such as molecular sieves havingthe MFI framework structure (e.g., ZSM-5), the FAU framework structure(e.g., zeolite Y), or a molecular sieve based on any other convenientframework structure.

In other aspects, a monolith or other large structure containing and/orcomposed of the zeolite crystals may be used. For example, any of theadsorbent and/or membrane structures described above can be suitable foruse in some catalysis applications. Optionally, such structures can alsoinclude other catalytic metals, such as other catalytic metalsimpregnated on the surface of the structure.

As a specific example, zeolite ITQ-55 can be useful in the catalyticconversion of oxygenates to one or more olefins, particularly ethyleneand propylene. As used herein, the term “oxygenates” is defined toinclude, but is not necessarily limited to aliphatic alcohols, ethers,carbonyl compounds (aldehydes, ketones, carboxylic acids, carbonates,and the like), and also compounds containing hetero-atoms, such as,halides, mercaptans, sulfides, amines, and mixtures thereof. Thealiphatic moiety will normally contain from about 1 to about 10 carbonatoms, such as from about 1 to about 4 carbon atoms.

Representative oxygenates include lower straight chain or branchedaliphatic alcohols, their unsaturated counterparts, and their nitrogen,halogen and sulfur analogues. Examples of suitable oxygenate compoundsinclude methanol; ethanol; n-propanol; isopropanol; C₄-C₁₀ alcohols;methyl ethyl ether; dimethyl ether; diethyl ether; di-isopropyl ether;methyl mercaptan; methyl sulfide; methyl amine; ethyl mercaptan;di-ethyl sulfide; di-ethyl amine; ethyl chloride; formaldehyde;di-methyl carbonate; di-methyl ketone; acetic acid; n-alkyl amines,n-alkyl halides, n-alkyl sulfides having n-alkyl groups of comprisingthe range of from about 3 to about 10 carbon atoms; and mixturesthereof. Particularly suitable oxygenate compounds are methanol,dimethyl ether, or mixtures thereof, most preferably methanol. As usedherein, the term “oxygenate” designates only the organic material usedas the feed. The total charge of feed to the reaction zone may containadditional compounds, such as diluents.

In an oxygenate conversion process, a feedstock comprising an organicoxygenate, optionally, with one or more diluents, is contacted in thevapor phase in a reaction zone with a catalyst comprising the molecularsieve of the present invention at effective process conditions so as toproduce the desired olefins. Alternatively, the process may be carriedout in a liquid or a mixed vapor/liquid phase. When the process iscarried out in the liquid phase or a mixed vapor/liquid phase, differentconversion rates and selectivities of feedstock-to-product may resultdepending upon the catalyst and the reaction conditions.

It is noted that both methanol and dimethyl ether can have a kineticdiameter that is at least similar to methane. At temperatures near 25°C. and pressures near 0.1 MPaa, methanol and/or dimethyl ether can havea limited ability to enter the pore structure of zeolite ITQ-55.However, as temperature and/or pressure is increased, methanol anddimethyl ether can have an increasing ability to enter the porestructure of ITQ-55, thus allowing for increasing ability to catalyzethe oxygenate to olefin reaction. Still further increases in temperatureand/or pressure may allow for conversion of other oxygenates, such asethanol. As a result, variations in temperature and/or pressure duringoxygenate to olefin conversion can allow for tuning of the conversionreaction.

As an example, an initial loading of methanol or dimethyl ether can beintroduced into a catalyst structure and/or catalyst particlescomprising ITQ-55 at a first pressure. At the first pressure, thepressure of methanol and/or dimethyl ether can be sufficient to load thecatalyst structure and/or catalyst particles. The pressure can then bereduced while maintaining a temperature where the methanol and/ordimethyl ether has a reduced or minimal amount of diffusion within theITQ-55 pore structure. This can result in an oxygenate being confinedwithin a constrained pore structure that may allow for selectiveproduction of ethylene at increased yield. Optionally, methane can beused in place of methanol and/or dimethyl ether, along with a suitableoxidant such as water or molecular oxygen.

When present, the diluent(s) is generally non-reactive to the feedstockor molecular sieve catalyst composition and is typically used to reducethe concentration of the oxygenate in the feedstock. Non-limitingexamples of suitable diluents include helium, argon, nitrogen, carbonmonoxide, carbon dioxide, water, essentially non-reactive paraffins(especially alkanes such as methane, ethane, and propane), essentiallynon-reactive aromatic compounds, and mixtures thereof. The mostpreferred diluents are water and nitrogen, with water being particularlypreferred. Diluent(s) may comprise from about 1 mol % to about 99 mol %of the total feed mixture.

The temperature employed in the oxygenate conversion process may varyover a wide range, such as from about 200° C. to about 1000° C., forexample, from about 250° C. to about 800° C., including from about 250°C. to about 750° C., conveniently from about 300° C. to about 650° C.,typically from about 350° C. to about 600° C., and particularly fromabout 400° C. to about 600° C.

Light olefin products will form, although not necessarily in optimumamounts, at a wide range of pressures, including but not limited toautogenous pressures and pressures in the range of from about 0.1 kPa toabout 10 MPaa. Conveniently, the pressure is in the range of from about7 kPa to about 5 MPaa, such as in the range of from about 50 kPa toabout 1 MPaa. The foregoing pressures are exclusive of diluent, if anyis present, and refer to the partial pressure of the feedstock as itrelates to oxygenate compounds and/or mixtures thereof. Lower and upperextremes of pressure may adversely affect selectivity, conversion,coking rate, and/or reaction rate; however, light olefins such asethylene still may form.

The process can be continued for a period of time sufficient to producethe desired olefin products. The reaction time may vary from tenths ofseconds to a number of hours. The reaction time is largely determined bythe reaction temperature, the pressure, the catalyst selected, theweight hourly space velocity, the phase (liquid or vapor) and theselected process design characteristics.

A wide range of weight hourly space velocities (WHSV) for the feedstockcan be used in the oxygenate conversion process. WHSV is defined asweight of feed (excluding diluent) per hour per weight of a totalreaction volume of molecular sieve catalyst (excluding inerts and/orfillers). The WHSV generally should be in the range of from about 0.01hr⁻¹ to about 500 hr⁻¹, such as in the range of from about 0.5 hr⁻¹ toabout 300 hr⁻¹, for example, in the range of from about 0.1 hr⁻¹ toabout 200 hr⁻¹.

A practical embodiment of a reactor system for the oxygenate conversionprocess is a circulating fluid-bed reactor with continuous regeneration,similar to a modern fluid catalytic cracker. Fixed beds are generallynot preferred for the process because oxygenate to olefin conversion isa highly exothermic process which requires several stages withintercoolers or other cooling devices. The reaction also results in ahigh pressure drop due to the production of low pressure, low densitygas.

Because the catalyst in such an oxygenate to olefin process must beregenerated frequently, the reactor should allow easy removal of aportion of the catalyst to a regenerator, where the catalyst issubjected to a regeneration medium, such as a gas comprising oxygen, forexample, air, to burn off coke from the catalyst, which restores thecatalyst activity. The conditions of temperature, oxygen partialpressure, and residence time in the regenerator should be selected toachieve a coke content on regenerated catalyst of less than about 0.5 wt%. At least a portion of the regenerated catalyst should be returned tothe reactor.

As another example, catalysts that are effective for conversion ofmethanol (and/or other oxygenates) to olefins are often also effectivefor conversion of methanol and/or other oxygenates to aromaticcompounds. Reaction conditions for formation of aromatics from methanolare often similar to reaction conditions for formation of olefins, witharomatics formation sometimes being favored by conditions that tendtoward higher severity. Thus, in some aspects, conditions that can favoraromatics formation can include lower WHSV values, higher temperatures,and/or higher partial pressures of reactants. Aromatic products cangenerally include C₆ to C₁₁ aromatics, with C₆, C₇, and/or C₈ aromaticsoften being preferred. For example, preferred products can includebenzene (C₆), toluene (C₇), and/or xylene (C₈).

This invention is illustrated by means of the following examples that donot seek to be restrictive thereof.

EXAMPLES Example 1 Preparation of theN²,N²,N²,N⁵,N⁵,N⁵,3a,6a-octamethyloctahydropentalene-2,5-diammoniumdihydroxide

To a recently prepared and thoroughly mixed solution of 5.6 g NaHCO₃ in360.0 mL of H₂O (pH=8) is added 48.2 mL (526.3 mmol) of dimethyl1,3-acetonedicarboxylate followed by 23.0 mL (263.2 mmol) of2,3-butanodione. The mixture remains under continuous stirring for 72hr. After this period the abundant precipitate obtained is filteredunder vacuum and cooled in a bath of ice, being acidified to pH=5 withHCl (5%). The raw precipitate is extracted three times with CHCl₃,washing the set of organic phases with brine and drying them on MgSO4.The mixture is filtered through folded filter and the filtrate obtainedconcentrated under vacuum and used in the following stage withoutadditional purification.

The resultant solid is suspended in a mixture of 300.00 mL of HCl (1M)and 30.0 mL of glacial acetic acid and thereafter heated under refluxfor 24 hr. The resulting mixture is cooled first to room temperature andthen in an ice bath, extracting thereafter five time with CH₂Cl₂, dryingthe set of organic phases over MgSO₄. The rough precipitate obtained isfiltered through folded filter and concentrated under vacuum obtaining32.7 g (75%) of the desired diketone,3a,6a-dimethyltetrahydropentalene-2,5(1H,3H)-dione.

This diketone is transformed into the corresponding diamine by means ofthe method that is described below. 350.0 mL of a solution 1.0 M ofdimethylamine in methanol is cooled in an ice bath and onto it isdripped a solution of HCl 5 N in MeOH until obtaining pH=7-8. Then 16.7g is added (100.7 mmol) of the previously prepared diketone dissolved inthe minimum possible quantity of MeOH, followed by 10.2 g (161.2 mmol)of NaBH₃CN. The temperature is allowed to rise to room temperature andremains under continuous stirring for 72 hr.

The possible excess of NaBH₃CN is neutralized by adding HCl 5 N in MeOHuntil reaching pH=2, displacing the HCN formed with a stream of N₂ untila saturated solution in KOH. The mixture is partially concentrated undervacuum and the rough resultant is basified with a solution of KOH (25%)until reaching pH=12 and it is saturated with NaCl. The rough resultantobtained is extracted three times with CH₂Cl₂, drying the set of organicphases on MgSO₄. It is concentrated under vacuum obtaining 21.4 g (95%)of the desired diamine, N²,N²,N⁵,N⁵,3a,6ahexamethyloctahydropentalene-2,5-diamine.

Subsequently, the diamine is transformed into the quaternary diammoniumketone. For that, 21.6 g of the previously obtained diamine is dissolvedin 100.0 mL of MeOH and to it is added slowly, by means of a compensatedpressure funnel, 45.0 mL (722.8 mmol) of CH₃I diluted in 40.0 mL ofMeOH. Almost immediately a yellowish precipitate appears. The mixtureremains under continuous stirring for 72 hr and then 45.0 ml is added(722.8 mmol) of CH₃I remaining under continuous stirring untilcompleting one week. The precipitate obtained is filtered under vacuumwashing with abundant diethyl ether, providing 37.1 g of the quaternaryammonium salt desired in iodide form,N²,N²,N²,N⁵,N⁵,N⁵,3a,6a-octamethyloctahydropentalene-2,5-diammoniumdiiodide.

The filtrate is concentrated under vacuum and the viscous solid obtainedis washed with abundant acetone, a new precipitate appears that afterfiltering and drying under vacuum provides another 2.0 g of the ammoniumsalt (80%).

The iodide of the cation is exchanged by hydroxide using an ionicexchange resin in accordance with the following method: 20 g (44 mmol)of iodide of the cation (RI₂) is dissolved in water. To the solutionobtained is added 89 g of Dowex SBR resin and it remains under stirringuntil the following day. Subsequently, it is filtered, it is washed withdistilled water and a solution of N²,N²,N²,N⁵,N⁵,N⁵,3a,6a dihydroxide isobtained-octamethyloctahydropentalene-2,5-diammonium (R(OH)2) that istitrated with HCl (aq.), using phenolphthalein as indicator, anefficiency being obtained in the exchange greater than 92%.

The final solution contains 0.47 equivalent of hydroxide per 1000 g ofsolution.

Example 2 Zeolite Preparation ITQ-55

6 g is added of an aqueous solution of colloidal silica at 40% (LudoxACE-40) to 42.5 g of a solution ofN²,N²,N²,N⁵,N⁵,N⁵,3a,6a-octamethyloctahydropentalene 2,5-diammoniumdihydroxide-(R(OH)₂) that contains 0.47 equivalent of hydroxide in 1000g. The mixture is left evaporating under stirring until completeelimination of the surplus water until reaching the final compositionthat is indicated. Finally, a solution of 0.74 g of ammonium fluoride isadded in 2.5 g of water. The composition of the gel is:

SiO₂:0.25R(OH)₂:0.5 NH₄F:5H₂O.

The mixture obtained is introduced in an autoclave provided with aninternal sleeve of polytetrafluorethylene and is warmed at 150° C. over10 days in an electrical furnace provided with a rotation system. TheX-ray diffractogram of the solid obtained on filtering, washing withdistilled water and drying at 100° C. is shown in FIG. 1 and presentsthe listing of the most characteristic peaks that appears in the TableIII. The calcining at 800° C. in air for 3 hours allows eliminating theoccluded organic species. The X-ray diffraction pattern of the calcinedzeolite ITQ-55 is shown in FIG. 2 and presents the most characteristicpeaks that appears in Table IV and indicates that the material is stableduring this process.

Example 3 Zeolite Preparation ITQ-55

8 g of tetraethylorthosilicate (TEOS) is added to 40.8 g of a solutionof N²,N²,N²,N⁵,N⁵,N⁵,3a,6a-octamethyloctahydropentalene-2,5-diammoniumdihydroxide (R(OH)2) that contains 0.47 equivalent of hydroxide in 1000g. The mixture is left evaporating under stirring until completeelimination of the ethanol coming from the hydrolysis of the TEOS plusthe quantity of water necessary until reaching the final compositionthat is indicated. Finally, 0.77 g of a solution of hydrofluoric acid isadded (50% of HF by weight). The composition of the gel is:

SiO₂:0.25R(OH)₂:0.5 HF:5H₂O.

The mixture obtained is introduced into a autoclave provided with aninternal sleeve of polytetrafluoroethylene and is warmed at 15 over 10days in an electrical furnace provided with a rotation system. The solidobtained on filtering, washing with distilled water and drying at 100°C. is ITQ-55.

Example 4 Zeolite Preparation ITQ-55

6 g is added from a aqueous solution of colloidal silica at 40% (LudoxACE-40) 42.5 g of a solution ofN²,N²,N²,N⁵,N⁵,N⁵,3a,6a-octamethyloctahydropentalene-2,5-diammonium(R(OH)2) dihydroxide that contains 0.47 equivalent of hydroxide in 1000g. Thereafter 0.14 g of aluminum hydroxide is added (57% Al₂O₃) and themixture is left evaporating under stirring until complete elimination ofthe surplus water until reaching the final composition that isindicated. Finally, a solution of 0.74 g of ammonium fluoride is addedin 2.5 g of water. The composition of the gel is:

SiO₂:0.02 Al₂O₃:0.25R(OH)₂:0.5 NH₄F:5H₂O.

The mixture obtained is introduced in an autoclave provided of aninternal sleeve of polytetrafluoroethylene and is warmed at 150° C. over14 days in an electrical furnace provided with a rotation system. Thesolid obtained on filtering, washing with distilled water and drying at100° C. presents the diffractogram of X-rays that is shown in FIG. 3 andindicates that it is zeolite ITQ-55.

Example 5 Zeolite Preparation ITQ-55

To 0.087 g of Ti tetraethoxide (IV) (TEOTi) is added 8 g oftetraethylorthosilicate (TEOS). Next 40.8 g of a solution ofN²,N²,N²,N⁵,N⁵,N⁵,3a,6a-octamethyloctahydropentalene-2,5-diammoniumdihydroxide (R(OH)₂) is added that contains 0.47 equivalent of hydroxidein 1000 g. The mixture is left evaporating under stirring until completeelimination of the ethanol coming from the hydrolysis of TEOS and TEOTiplus the quantity of water necessary until reaching the finalcomposition that is indicated. Finally, 0.77 g of a solution ofhydrofluoric acid is added (50% of HF by weight). The composition of thegel is:

SiO₂:0.01 TiO₂:0.25R(OH)₂:0.5HF:5H₂O.

The mixture obtained is introduced in a autoclave provided with aninternal sleeve of polytetrafluoroethylene and is warmed at 150° C. over14 days in an electrical furnace provided with a rotation system. Thesolid obtained on filtering, washing with distilled water and drying at100° C. is ITQ-55.

Example 6 Zeolite Preparation ITQ-55

6 g is added from a aqueous solution of colloidal silica at 40% (LudoxACE-40) 42.5 g of a solution ofN²,N²,N²,N⁵,N⁵,N⁵,3a,6a-octamethyloctahydropentalene-2,5-diammoniumdihydroxide (R(OH)₂) that contains 0.47 equivalent of hydroxide in 1000g. Next 0.1 g of H₃BO₃ is added and the mixture is left evaporatingunder stirring until complete elimination of the surplus water untilreaching the final composition that is indicated. Finally, a solution of0.74 g of ammonium fluoride is added in 2.5 g of water. The compositionof the gel is:

SiO₂:0.02B₂O₃:0.25R(OH)2:0.5NH₄F:5H₂O.

The mixture obtained is introduced into a autoclave provided with aninternal sleeve of polytetrafluoroethylene and is warmed at 150° C. over14 days in an electrical furnace provided with a rotation system. Thesolid obtained on filtering, washing with distilled water and drying at100° C. is zeolite ITQ-55.

Example 7 Zeolite Preparation ITQ-55

To 8 g of tetraethylorthosilicate (TEOS) is added 36.6 g of a solutionof N²,N²,N²,N⁵,N⁵,N⁵,3a,6a-octamethyloctahydropentalene-2,5-diammoniumdihydroxide (R(OH)₂) that contains 0.53 equivalent of hydroxide in 1000g. Next 0.0476 g of H₃BO₃ is added. The mixture is left evaporatingunder stirring until complete elimination of the ethanol coming from thehydrolysis of the TEOS plus the quantity of water necessary untilreaching the final composition that is indicated. The composition of thegel is:

SiO₂:0.01B₂O₃:0.25R(OH)₂:10H₂O.

The mixture obtained is introduced in an autoclave provided of aninternal sleeve of polytetrafluoroethylene and is warmed to 150° C. over14 days in an electrical furnace provided with a rotation system. Thesolid obtained on filtering, washing with distilled water and drying at100° C. is ITQ-55.

Example 8 Zeolite Preparation ITQ-55

To 8 g of tetraethylorthosilicate (TEOS) is added 36.3 g of a solutionof N²,N²,N²,N⁵,N⁵,N⁵,3a,6a-octamethyloctahydropentalene-2,5-diammoniumdihydroxide (R(OH)2) that contains 0.532 equivalent of hydroxide in 1000g. Next 0.805 g of GeO₂ is added. The mixture is left evaporating understirring until complete elimination of the ethanol coming from thehydrolysis of the TEOS plus the quantity of water necessary untilreaching the final composition that is indicated. The composition of thegel is:

SiO₂:0.2GeO₂:0.25R(OH)₂:10H₂O.

The mixture obtained is introduced in a autoclave provided with aninternal sleeve of polytetrafluoroethylene and is warmed at 150° C. over14 days in an electrical furnace provided with a rotation system. Thesolid obtained on filtering, washing with distilled water and drying at100° C. is ITQ-55.

Example 9 Adsorption of CO₂ at 30° C. In the ITQ-55 Material of Example2

The measurement of the adsorption capacity of CO₂ of the ITQ-55material, prepared according to the example 2, at 30° C. and 9 barcorresponds to 2.96 mmoles/g. Likewise, the value obtained aftercarrying out 20 adsorption/desorption cycles is of 2.95 mmoles/g, whichdemonstrates that the material ITQ-55 conserves its adsorption capacityafter a high number of cycles.

Example 10 Adsorption of CO₂ at 60° C. In the ITQ-55 Material of Example2

The measurement of the CO₂ adsorption capacity of the ITQ-55 material,prepared according to the example 2, at 60° C. and 9 bar corresponds to2.35 mmoles/g.

Example 11 Methane Adsorption at 60° C. In the ITQ-55 Material ofExample 2

The measurement of the methane adsorption capacity of the ITQ-55material, prepared according to the example 2, at 60° C. and 9 barcorresponds to 0.22 mmoles/g, after equilibrating for 24 hours at thistemperature and pressure.

Example 12 Methane Adsorption at 30° C. In the ITQ-55 Material ofExample 2

The measurement of the methane adsorption capacity of the ITQ-55material, prepared according to the example 2, at 30° C. and 9 barcorresponds to 0.18 mmoles/g after equilibrating for 24 hours at thistemperature and pressure. The lowest adsorption capacity under theseconditions regarding the one observed in the example 5 indicates thedrop in diffusion capacity of the methane through the zeolite ITQ-55pores.

Example 13 Determination of the Selectivity in the Separation of CO₂ andMethane in the ITQ-55 Material of Example 2

The selectivity in methane and CO₂ separation has been consideredthrough the ratio of the adsorption values of the isotherms of the puregases of CO₂ and methane at identical pressure and temperature. It isconsidered that the selectivity in the separation process will be betterinsofar as the ratio between these values is greater. In the FIG. 4 thevariation of this ratio is shown with the gas pressure at differenttemperatures.

Example 14 Ethane Adsorption at 30° C. In the ITQ-55 Material of Example2

The measurement of the adsorption capacity of ethane of the ITQ-55material, prepared according to the example 2, at 30° C. and 9 barcorresponds to 0.14 mmoles/g after equilibrating for 24 hours at thistemperature and pressure.

Example 15 Ethylene Adsorption at 30° C. In the ITQ-55 Material ofExample 2

The measurement of the ethylene adsorption capacity of the ITQ-55material, prepared according to the example 2, at 30° C. and 9 barcorresponds to 0.75 mmoles/g after equilibrating for 24 hours at thistemperature and pressure.

Process Example 1 Modeling of Zeolite Structure Fluctuations

In order to further investigate the pore structure of ITQ-55, moleculardynamics simulations of the ITQ-55 structure were performed on a unitcell, with density functional theory being used to determine theinteractions between the atoms in the unit cell. A repeating cellboundary condition was used to effectively provide an “infinite”lattice. The molecular dynamics simulations were performed in the NPTensemble to allow for volume fluctuations of the unit cell. Usingdensity functional theory, an optimized unit cell structure in Angstromswas calculated of 22.58 (a); 13.51 (b); and 14.74 (c). This iscomparable to the unit cell structure determined by X-ray diffraction,which was 22.39 (a); 13.34 (b); 14.5 (c). With regard to the size of thesmallest pore window, the minimum size window determined by densityfunctional theory for an optimized structure was 2.37 Angstroms. Thesmallest pore window determined from the X-ray diffraction data was 2.07Angstroms (minimum). It is noted that either of these minimum dimensionsis substantially smaller than the size of several molecules (such as N₂and CO₂) that are observed as being adsorbed within the ITQ-55 porenetwork.

FIG. 11 shows how the size of the unit cell fluctuated during amolecular dynamics simulation where density functional theory was usedfor interaction potentials. In FIG. 11, lines 1110, 1120, and 1130 showthe a, b, and c parameters (in Angstroms) respectively of the unit cellas determined from X-ray diffraction data. Lines 1112, 1122, and 1132show the a, b, and c parameters respectively of the unit cell for theoptimized structure as determined by density functional theory. Lines1114, 1124, and 1134 show the a, b, and c parameters respectively of theunit cell as it fluctuates during an NPT ensemble molecular dynamicssituation at a temperature of 300 K. As shown in FIG. 11, the “c”parameter of the unit cell showed the largest variation in size betweenthe optimized DFT structure and the size variations calculated at 300 K.

FIG. 12 shows additional results from molecular dynamics simulationsrelated to the minimum aperture (or pore) size in the unit cell. FIG. 12shows changes in the distance between oxygen atoms on opposite sides ofthe smallest 8-member ring in the unit cell structure during moleculardynamics simulations at various temperatures. The simulationtemperatures correspond to 200 K (1210), 300 K (1220), 400 K (1230), 600K (1240), and 1100 K (1250). It is noted that the total amount of timesimulated to generate the results in FIG. 12 corresponds to about 6picoseconds. In spite of the short amount of time, the size of theminimum pore distance can vary substantially, as shown in FIG. 12. Inparticular, at the higher temperatures the largest minimum pore distancecalculated by the simulations approaches 3.6 Angstroms, whichcorresponds to the size of the largest molecules (such as N₂) that arebelieved to be able to enter the ITQ-55 pore network. Without beingbound by any particular theory, the simulation results at the highertemperatures may tend to show the ability of the ITQ-55 minimum sizepore channel to expand, so that some larger molecules can enter, whileexcluding other molecules beyond a cutoff size. It is also noted that asthe temperature decreases, the average size of the minimum distanceappears to increase (as shown by the location of the peak maximum), butthe amount of fluctuation around the average size decreases (narrowerdistribution).

Process Example 2 Adsorption Characteristics

FIG. 13 shows adsorption isotherms at 28° C. for ITQ-55 crystals atpressures near ambient. In FIG. 13, the amount of an adsorbed componentin mmol per gram of ITQ-55 is shown relative to pressure. As shown inFIG. 13, CO₂ is readily adsorbed by ITQ-55. N₂ and Ar are also adsorbed,although in smaller amounts. By contrast, substantially no adsorption ofmethane is observed at 28° C. The isotherms in FIG. 13 appear to showthat ITQ-55 can be suitable for separation of CO₂, N₂, or Ar from largermolecules such as methane. Additionally, the isotherms in FIG. 13suggest that separations of CO₂ from N₂ may also be feasible.

FIG. 14 shows adsorption isotherms for CO₂ and N₂ for an expanded rangeof pressures at 30° C. As shown in FIG. 14, ITQ-55 appears to have asubstantial capacity for CO₂ and N₂ adsorption as pressure increases.The data in FIG. 14 suggests that equilibrium separations involving CO₂and N₂ may be limited in selectivity.

FIG. 15 shows the isosteric heats of adsorption for CO₂ and N₂. As shownin FIG. 15, the heat of adsorption for CO₂ appears to be about twice thevalue of the heat of adsorption for N₂, with the heat of adsorptionbeing mostly independent of the amount of prior uptake.

FIG. 16 shows the equilibrium loading of N₂ in mol per kg of ITQ-55 at5° C. and 25° C. As shown in FIG. 16, ITQ-55 appears to have anincreased adsorption capacity for N₂ as temperature is decreased. Basedon the minimal adsorption of methane and larger hydrocarbons by ITQ-55,FIG. 16 suggests that ITQ-55 can be suitable for performing selectiveseparations of N₂ from methane (or larger compounds) at temperaturesnear ambient or below ambient.

FIG. 17 shows the equilibrium loading of H₂O for ITQ-55 in comparisonwith zeolite 5A, a conventional zeolite used for separations. As shownin FIG. 17, ITQ-55 has a lower capacity for uptake of water incomparison with conventional zeolites. This can be beneficial forreducing or minimizing water adsorption during separation processesinvolving two other components where water is a trace component in a gasstream.

FIG. 18 shows adsorption isotherms at 28° C. for C₂H₄, Ar, Kr, and CH₄.Similar to FIG. 13, minimal or even no adsorption of CH₄ is observed.This is in contrast to ethylene, which is adsorbed sufficiently tosuggest that ITQ-55 can be suitable for separations of ethylene frommethane. Ar and Kr also show sufficient adsorption to be separable frommethane and larger hydrocarbons.

FIG. 19 shows a comparison of equilibrium adsorption of methane andethylene at 1 bara (101 kPa) and 28° C. As shown in FIG. 19, ITQ-55 hasa substantial selectivity for adsorption of ethylene with respect tomethane.

FIG. 20 shows adsorption isotherms for H₂ at up to 10 bar (about 1 MPaa)at −10° C. and CH₄ at 28° C. Similar to other comparisons, H₂ isadsorbed in substantially greater amounts than CH₄. The data in FIG. 20suggests that ITQ-55 can be suitable for kinetic separations of H₂ fromCH₄.

Although ITQ-55 provides only minimal adsorption of CH₄, from a kineticstandpoint any adsorption of CH₄ that does occur appears to be fasterthan adsorption of ethylene. FIG. 21 shows adsorption as a function ofthe square root of time at 1 bar (101 kPa) and 30° C. for CO₂ (2110), N₂(2120), CH₄ (2130), and C₂H₄ (2140). FIG. 21 also shows a curve fitbased on a diffusion model (2150) for CO₂ adsorption. The x-axis isselected based on the typical relationship of diffusion to the squareroot of time. The y-axis is normalized relative to the amount ofadsorption to allow for ease of comparison of diffusion rates. As shownin FIG. 21, N₂ and CO₂ are adsorbed more rapidly than CH₄, but ethyleneis actually adsorbed more slowly.

Table 101 shows diffusivity values calculated based on the measuredadsorption values in FIG. 21. The diffusivity values in Table 101 werecalculated for an ITQ-55 crystal size of 60 μm. Based on the diffusivityvalues, Table 101 also shows kinetic selectivities. As shown in Table101, ITQ-55 shows an unexpectedly high kinetic selectivity for CO₂relative to CH₄.

TABLE 101 Diffusion time constants D/R² [1/s] of N₂, CO₂, CH₄, C₂H₄ andC₂H₆ in 60 μm crystals of ITQ-55 shown in FIG. 23A and 23B measured at30° C., and ideal kinetic selectivities. CO₂/CH₄ N₂/CH₄ C₂H₄/C₂H₆kinetic kinetic kinetic N₂ CO₂ CH₄ C₂H₄ C₂H₆ selectivity selectivityselectivity 2.4 × 10⁻⁴ 3.3 × 10⁻³ <1.0 × 10⁻⁵ 3.0 × 10⁻⁷ <6.6 ×10⁻⁹ >300 >20 >40

FIG. 22 shows additional data related to uptake as a function of timefor N₂ (2210), CO₂(2220), CH₄ (2230), C₂H₆ (2240), and C₂H₄ (2250). Thedata in FIG. 22 corresponds to uptake at 700 mbar (70 kPa), with theexception of N₂ which is at 1000 mbar (101 kPa). As shown in FIG. 22,little or no uptake of CH₄ and C₂H₆ occurs. Both C₂H₄ and N₂ show slowuptake over time, with a more substantial loading of C₂H₄ being achievedat long time periods. Adsorption of CO₂ is more rapid than theadsorption of either C₂H₄ or N₂, suggesting the ability to performkinetic separations for CO₂ relative to these components.

Equilibrium adsorption selectivities were also calculated. Table 102shows uptake values calculated based on the measured adsorption valuesin FIG. 22. It is noted that CH₄ and C₂H₆ both show very low adsorptionon ITQ-55. Based on the uptake values, Table 102 also shows adsorptionselectivities. As shown in Table 102, ITQ-55 shows an unexpectedly highadsorption selectivity for CO₂ relative to CH₄.

TABLE 102 Uptake capacity of N₂, CO₂, CH₄, C₂H₄ and C₂H₆ on ITQ-55measured at 30° C. and ideal adsorption selectivities. N₂ CO₂ CH₄ C₂H₄C₂H₆ uptake, uptake, uptake*, uptake, uptake*, CO₂/CH₄ N₂/CH₄ C₂H₄/C₂H₆mmol/g mmol/g mmol/g mmol/g mmol/g adsorption adsorption adsorption(pressure) (pressure) (pressure) (pressure) (pressure) selectivityselectivity selectivity 0.16 0.94 0.015 0.40 0.08 62.7 10.7 5.0 (970mbar) (536 mbar) (600 mbar) (570 mbar) (595 mbar)

FIG. 28 shows calculated adsorption isotherms for acetylene on ITQ-55.Acetylene is believed to have a kinetic diameter similar to CO₂ and istherefore expected to be able to enter/diffuse into the pore structureof ITQ-55. In order to investigate the adsorption of acetylene, GrandCanonical Monte Carlo simulations were performed for adsorption ofacetylene on an ITQ-55 crystal surface. As a comparison, simulationswere also performed for adsorption of CO₂ and N₂ in order to calculateadsorption isotherms. As shown in FIG. 28, acetylene (C₂H₂) is predictedto be adsorbed in larger amounts than N₂, but in lower amounts relativeto CO₂, for the low pressure range of about 0 bar to about 30 bar (3MPaa).

Process Example 3 Additional SEM Characterization

FIGS. 23A and 23B show scanning electron microscopy (SEM) images ofITQ-55 crystals. The images show large layered crystals with a size ofabout 50 μm to about 70 μm.

Process Example 4 Diffusion Characteristics

FIGS. 24 and 25 show kinetic studies with frequency response for CH₄ andCO₂ (FIG. 24) and N₂ (FIG. 25) on an ITQ-55 sample. FIG. 24 correspondsto CH₄ and CO₂ at 30° C. and a pressure of 0.1 bar (10 kPa). In FIG. 24,the line fit to the CH₄ data corresponds to line 2411, while the linefit for the CO₂ data corresponds to line 2421. The results show that CH₄on ITQ-55 behaves like He with no visual adsorption apparent for thefrequency ranges studied. The CO₂ diffusion time constant in 60 μmcrystals of the ITQ-55 sample shown in FIGS. 23A and 23B is 0.003/s.

FIG. 25 corresponds to N₂ adsorption at three temperatures of −70° C.(2510), −20° C. (2520), 30° C. (2530) and same pressure of 1 bar (101kPa). For comparison, He adsorption at 30° C. and 1 bar is also shown(2540). At low frequencies, the frequency response curves approachplateau to reflect equilibrium status and isotherm slope can bequantified by the difference between plateau of N₂ and Heliumexperiments. The results shows N₂ adsorbs more at −70° C. but withslower diffusivities. N₂ has ˜3 times more capacity at −70° C. comparedto 30° C. The N₂ diffusion time constant in 60 μm crystals of the ITQ-55sample shown in FIGS. 23A and 23B is 0.0004/s at 30° C. and slows downto 0.00028/s at −20° C. Comparing diffusivity of N₂ and CO₂ at similarconditions (30° C.), the kinetic selectivity is about 8. Also, largerkinetic selectivity is for separation of N₂ and CH₄/CO₂.

FIG. 27 shows ZLC results for CO₂ in ITQ-55. The ZLC experiments wereperformed in a small chromatographic column using 10% CO₂ in helium. Theexperimental data with a partial loading experiment 2721 was fitted witha ZLC model 2722, and the full equilibration experiment 2711 waspredicted with the model 2712 using the same parameters. The diffusionrate in 60 μm crystals of the ITQ-55 sample shown in FIGS. 23A and 23Bhas been quantified as 0.003 sec⁻¹.

In FIG. 26, the temperature dependence of diffusion time constants forethane and ethylene was estimated from single-gas uptake experimentsconducted on a HIDEN IMI volumetric gas sorption apparatus availablefrom Hiden Isochema. Zeolite ITQ-55 was first activated at 300° C. underdynamic vacuum for 4 hours to remove moisture and previously adsorbedspecies, then cooled down to a selected temperature. Target gas wasintroduced into the sample cell at 1.1 bar. Gradual pressure drop in thesample cell was accounted for as gas adsorption on the zeolite. Themeasured gas uptake curve was used to estimate the diffusion timeconstant. Although equilibrium loading was not reached at the conditionsshown in FIG. 26, simulated values were used to determine theequilibrium loading. The procedure was repeated at the next temperatureand/or for the next adsorbate gas. As shown in FIG. 26, the temperaturedependence of diffusion time constant shows higher activation energy ofdiffusion for ethane relative to ethylene. At temperatures near 25° C.,ethylene appears to have a higher kinetic selectivity of about 50. Astemperature increases, FIG. 26 shows that the kinetic selectivity forethylene relative to ethane decreases.

Prophetic Example 1 Separation of N₂ from Methane, Natural Gas, andOther Hydrocarbons

The following is a prophetic example. Natural gas deposits can ofteninclude nitrogen as part of the total gas composition. Additionally,during extraction of natural gas, nitrogen can be introduced into a wellto assist with extraction. This process can sometimes be referred to as“nitrogen flooding”. As a result, natural gas can often include nitrogenas a “contaminant”. Nitrogen is generally not harmful to many naturalgas uses, but nitrogen can act as a diluent, reducing the fuel value ofa natural gas feed. Thus, it can be beneficial to reduce or minimize thenitrogen content of a natural gas feed. It is noted that natural gas cantypically contain a substantial portion of methane, along with a varietyof other small (C2-C4) hydrocarbons. Thus, the techniques describedherein for separation of nitrogen from natural gas can also be suitablemore generally for separation of nitrogen from methane, ethane, andother organic compounds containing three or more heavy atoms. Thesetechniques can also be suitable for separation of nitrogen from ethyleneand/or acetylene, although the selectivities may be different than theselectivities for alkanes or alcohols.

Nitrogen can be separated from natural gas (or other streams containingalkanes/organic compounds) using an adsorbent and/or membrane thatincludes zeolite ITQ-55. Adsorption can be performed using anyconvenient type of process, such as a swing adsorption process. Forseparation by adsorption, a natural gas (or other stream containingalkanes/organic compounds) that also contains nitrogen can be exposed toan adsorbent structure. The surface of the adsorbent structure can becomposed of and/or include zeolite ITQ-55 in a manner so that fluidsthat enter the adsorbent structure can enter by passing through pores ofthe ITQ-55. Depending on the adsorbent structure, defects in the ITQ-55crystal structure and/or defects between crystals can allow some fluidsto enter the adsorbent structure without passing through the ITQ-55. Dueto such defects, less than 100% of the fluids entering the adsorbentstructure may pass through the ITQ-55 crystals, such as at least about90 vol %, or at least about 95%, or at least about 98%.

Similarly, for separation by permeation through a membrane, a naturalgas (or other stream containing alkanes/organic compounds) that alsocontains nitrogen can be exposed to a membrane structure. The surface ofthe membrane structure can be composed of and/or include zeolite ITQ-55in a manner so that fluids that enter the membrane structure can enterby passing through pores of the ITQ-55. Depending on the adsorbentstructure, defects in the ITQ-55 crystal structure and/or defectsbetween crystals can allow some fluids to enter the membrane structurewithout passing through the ITQ-55. Due to such defects, less than 100%of the fluids entering the membrane structure may pass through theITQ-55 crystals, such as at least about 90 vol %, or at least about 95%,or at least about 98%.

During a separation process, a fluid comprising natural gas (or otherhydrocarbon or organic components) and nitrogen can be exposed to anadsorbent or membrane structure. Based on the kinetic diameter and/orthe affinity of nitrogen for the ITQ-55, the nitrogen can preferentiallyenter the adsorbent or membrane structure relative to methane or otherorganic compounds. This can allow for selectivity for nitrogen overmethane or another organic compound, either for adsorption or forseparation via membrane, of at least about 5, or at least about 10, orat least about 20, or at least about 30.

Optionally, the adsorption separation or membrane can be performed at atemperature below 300 K, such as 275 K or less, or 250 K or less, or 225K or less, or 200 K or less. This can enhance the selectivity of theITQ-55 for performing the separation, as well as potentially increasingthe capacity of an adsorbent structure for holding nitrogen. Optionally,performing a separation at low temperature can also benefit fromallowing water to be condensed out of a fluid prior to the fluid beingexposed to the adsorbent or membrane structure. Optionally, a lowtemperature separation can be performed at any convenient pressure, suchas a pressure of 1000 bar (100 MPaa) or less. It is noted that at theseseparation conditions, the fluid being separated can optionallycorrespond to a liquid.

As another option, the separation can be performed at a temperature ofabout 270 K to about 375 K and at a pressure of about 700 bar (70 MPaa)or less, or about 500 bar (50 MPaa) or less, or about 300 bar (30 MPaa)or less, or about 100 bar (10 MPaa) or less. Under these conditions,entry of methane or other organic compounds can be reduced, minimized,or possibly eliminated. The minimized entry of methane or other organiccompounds into the adsorbent structure or membrane structure canfacilitate performing a separation with high selectivity.

As still another option, the separation can be performed at atemperature greater than about 270 K, or greater than about 325 K, orgreater than about 375 K, such as up to about 600 K or more.Additionally or alternately, the separation can be performed at apressure greater than about 100 bar (10 MPaa), or greater than about 300bar (30 MPaa), or greater than about 500 bar (50 MPaa), or greater thanabout 700 bar (70 MPaa), such as up to about 1500 bar (150 MPaa) ormore. Additionally or alternately, the separation can be performed atany combination of a temperature and pressure range cited in thisparagraph. Under these conditions, some methane or other organiccompound may be able to enter an adsorbent structure or membranestructure, but the separation can be performed with a selectivity asdescribed above.

Prophetic Example 2 Separation of CO₂ from Methane, Natural Gas, andOther Hydrocarbons

The following is a prophetic example. Natural gas deposits can ofteninclude CO₂ as part of the total gas composition. CO₂ is generally notharmful to many natural gas uses, but CO₂ can act as a diluent, reducingthe fuel value of a natural gas feed. Additionally, for some natural gassources, CO₂ may be present due to injection of CO₂ into a hydrocarbonreservoir as part of an enhanced oil recovery process. Thus, it can bebeneficial to reduce or minimize the CO₂ content of a natural gas feed.It is noted that natural gas can typically contain a substantial portionof methane, along with a variety of other small (C2-C4) hydrocarbons.Thus, the techniques described herein for separation of CO₂ from naturalgas can also be suitable more generally for separation of nitrogen frommethane, ethane, and other organic compounds containing three or moreheavy atoms. These techniques can also be suitable for separation of CO₂from ethylene and/or acetylene, although the selectivities may bedifferent than the selectivities for alkanes or alcohols.

CO₂ can be separated from natural gas (or other streams containingalkanes/organic compounds) using an adsorbent and/or membrane thatincludes zeolite ITQ-55. Adsorption can be performed using anyconvenient type of process, such as a swing adsorption process. Forseparation by adsorption, a natural gas (or other stream containingalkanes/organic compounds) that also contains CO₂ can be exposed to anadsorbent structure. The surface of the adsorbent structure can becomposed of and/or include zeolite ITQ-55 in a manner so that fluidsthat enter the adsorbent structure can enter by passing through pores ofthe ITQ-55. Depending on the adsorbent structure, defects in the ITQ-55crystal structure and/or defects between crystals can allow some fluidsto enter the adsorbent structure without passing through the ITQ-55. Dueto such defects, less than 100% of the fluids entering the adsorbentstructure may pass through the ITQ-55 crystals, such as at least about90 vol %, or at least about 95%, or at least about 98%.

Similarly, for separation by permeation through a membrane, a naturalgas (or other stream containing alkanes/organic compounds) that alsocontains CO₂ can be exposed to a membrane structure. The surface of themembrane structure can be composed of and/or include zeolite ITQ-55 in amanner so that fluids that enter the membrane structure can enter bypassing through pores of the ITQ-55. Depending on the adsorbentstructure, defects in the ITQ-55 crystal structure and/or defectsbetween crystals can allow some fluids to enter the membrane structurewithout passing through the ITQ-55. Due to such defects, less than 100%of the fluids entering the membrane structure may pass through theITQ-55 crystals, such as at least about 90 vol %, or at least about 95%,or at least about 98%.

During a separation process, a fluid comprising natural gas (or otherhydrocarbon or organic components) and CO₂ can be exposed to anadsorbent or membrane structure. Based on the kinetic diameter and/orthe affinity of nitrogen for the ITQ-55, the CO₂ can preferentiallyenter the adsorbent or membrane structure relative to methane or otherorganic compounds. This can allow for selectivity for CO₂ over methaneor another organic compound, either for adsorption or for separation viamembrane, of at least about 5, or at least about 10, or at least about20, or at least about 30.

Optionally, the adsorption separation or membrane can be performed at atemperature below 300 K, such as 275 K or less, or 250 K or less, or 225K or less, or 200 K or less. This can enhance the selectivity of theITQ-55 for performing the separation, as well as potentially increasingthe capacity of an adsorbent structure for holding CO₂. Optionally,performing a separation at low temperature can also benefit fromallowing water to be condensed out of a fluid prior to the fluid beingexposed to the adsorbent or membrane structure. Optionally, a lowtemperature separation can be performed at any convenient pressure, suchas a pressure of 1000 bar (100 MPaa) or less. It is noted that at theseseparation conditions, the fluid being separated can optionallycorrespond to a liquid.

As another option, the separation can be performed at a temperature ofabout 270 K to about 375 K and at a pressure of about 700 bar (70 MPaa)or less, or about 500 bar (50 MPaa) or less, or about 300 bar (30 MPaa)or less, or about 100 bar (10 MPaa) or less. Under these conditions,entry of methane or other organic compounds can be reduced, minimized,or possibly eliminated. The minimized entry of methane or other organiccompounds into the adsorbent structure or membrane structure canfacilitate performing a separation with high selectivity.

As still another option, the separation can be performed at atemperature greater than about 270 K, or greater than about 325 K, orgreater than about 375 K, such as up to about 600 K or more.Additionally or alternately, the separation can be performed at apressure greater than about 100 bar (10 MPaa), or greater than about 300bar (30 MPaa), or greater than about 500 bar (50 MPaa), or greater thanabout 700 bar (70 MPaa), such as up to about 1500 bar (150 MPaa) ormore. Additionally or alternately, the separation can be performed atany combination of a temperature and pressure range cited in thisparagraph. Under these conditions, some methane or other organiccompound may be able to enter an adsorbent structure or membranestructure, but the separation can be performed with a selectivity asdescribed above.

Prophetic Example 3 Syngas Separations

The following is a prophetic example. Syngas typically refers to a gasmixture containing a combination of H₂, CO, CO₂, and H₂O. Optionally,syngas can sometimes refer to at least two of H₂, CO, CO₂, and H₂O, orat least three of H₂, CO, CO₂, and H₂O. Optionally, a syngas stream canalso contain one or more other components, such as N₂, CH₄, O₂, and/orother small hydrocarbons. For at least some uses of syngas, it can bebeneficial to reduce or minimize the content of components other thanH₂, CO, CO₂, and H₂O. Additionally or alternately, in some aspects itcan be beneficial to separate one or more syngas components from theremaining portion of a syngas stream. For example, it can be desirableto separate hydrogen from syngas for use as a fuel, or to separate CO₂from syngas so that the CO₂ can be used and/or sequestered.

Hydrogen can be separated from syngas (and optionally from othercomponents present in a syngas stream such as N₂ or CH₄) using anadsorbent and/or membrane that includes zeolite ITQ-55. Adsorption canbe performed using any convenient type of process, such as a swingadsorption process. For separation by adsorption, a syngas stream can beexposed to an adsorbent structure. The surface of the adsorbentstructure can be composed of and/or include zeolite ITQ-55 in a mannerso that fluids that enter the adsorbent structure can enter by passingthrough pores of the ITQ-55. Depending on the adsorbent structure,defects in the ITQ-55 crystal structure and/or defects between crystalscan allow some fluids to enter the adsorbent structure without passingthrough the ITQ-55. Due to such defects, less than 100% of the fluidsentering the adsorbent structure may pass through the ITQ-55 crystals,such as at least about 90 vol %, or at least about 95%, or at leastabout 98%.

Similarly, for separation of hydrogen by permeation through a membrane,a syngas stream can be exposed to a membrane structure. The surface ofthe membrane structure can be composed of and/or include zeolite ITQ-55in a manner so that fluids that enter the membrane structure can enterby passing through pores of the ITQ-55. Depending on the adsorbentstructure, defects in the ITQ-55 crystal structure and/or defectsbetween crystals can allow some fluids to enter the membrane structurewithout passing through the ITQ-55. Due to such defects, less than 100%of the fluids entering the membrane structure may pass through theITQ-55 crystals, such as at least about 90 vol %, or at least about 95%,or at least about 98%.

During a separation process, a fluid comprising syngas can be exposed toan adsorbent or membrane structure. Based on the kinetic diameter and/orthe affinity of hydrogen for the ITQ-55, the hydrogen can preferentiallyenter the adsorbent or membrane structure relative to other componentsof a syngas. This can allow for selectivity for hydrogen over othersyngas components, either for adsorption or for separation via membrane,of at least about 5, or at least about 10, or at least about 20, or atleast about 30.

Another option can be to separate CO₂ from syngas using an adsorbentand/or membrane that includes zeolite ITQ-55. Relative to other syngascomponents, CO₂ can be a component that is preferentially not adsorbed,so that the product with an increase in CO₂ concentration can be theportion of the stream that is not adsorbed. Adsorption can be performedusing any convenient type of process, such as a swing adsorptionprocess. For separation by adsorption, a syngas stream can be exposed toan adsorbent structure. The surface of the adsorbent structure can becomposed of and/or include zeolite ITQ-55 in a manner so that fluidsthat enter the adsorbent structure can enter by passing through pores ofthe ITQ-55. Depending on the adsorbent structure, defects in the ITQ-55crystal structure and/or defects between crystals can allow some fluidsto enter the adsorbent structure without passing through the ITQ-55. Dueto such defects, less than 100% of the fluids entering the adsorbentstructure may pass through the ITQ-55 crystals, such as at least about90 vol %, or at least about 95%, or at least about 98%.

Similarly, for separation of CO₂ using a membrane, a syngas stream canbe exposed to a membrane structure. Because other syngas components cantend to preferentially enter a membrane composed of ITQ-55, the streamenriched in CO₂ can correspond to the retentate of the membraneseparation. The surface of the membrane structure can be composed ofand/or include zeolite ITQ-55 in a manner so that fluids that enter themembrane structure can enter by passing through pores of the ITQ-55.Depending on the adsorbent structure, defects in the ITQ-55 crystalstructure and/or defects between crystals can allow some fluids to enterthe membrane structure without passing through the ITQ-55. Due to suchdefects, less than 100% of the fluids entering the membrane structuremay pass through the ITQ-55 crystals, such as at least about 90 vol %,or at least about 95%, or at least about 98%.

During a separation process, a fluid comprising syngas can be exposed toan adsorbent or membrane structure. Based on the kinetic diameter and/orthe affinity of CO₂ for the ITQ-55 relative to other syngas components,the CO₂ can preferentially not enter the adsorbent or membrane structurerelative to other components of a syngas. This can allow for selectivityfor CO₂ over other syngas components, either for adsorption or forseparation via membrane, of at least about 5, or at least about 10, orat least about 20, or at least about 30. It is noted that a syngasstream that additional contains other non-syngas components, such as N₂or CH₄, may benefit from two separation steps. A first step can separateCO₂, N₂, and CH₄ from the remaining syngas components as thenon-adsorbed or retentate stream. A second separation can then takeadvantage of the increased affinity of CO₂ for ITQ-55 relative to N₂and/or CH₄ to form an enriched adsorbed stream or permeate stream.

Optionally, the adsorption separation or membrane can be performed at atemperature below 300 K, such as 275 K or less, or 250 K or less, or 225K or less, or 200 K or less. This can enhance the selectivity of theITQ-55 for performing the separation, as well as potentially increasingthe capacity of an adsorbent structure for holding hydrogen and/or CO₂.Optionally, performing a separation at low temperature can also benefitfrom allowing water to be condensed out of a fluid prior to the fluidbeing exposed to the adsorbent or membrane structure. Optionally, a lowtemperature separation can be performed at any convenient pressure, suchas a pressure of 1000 bar (100 MPaa) or less. It is noted that at theseseparation conditions, the fluid being separated can optionallycorrespond to a liquid.

As another option, the separation can be performed at a temperature ofabout 270 K to about 375 K and at a pressure of about 700 bar (70 MPaa)or less, or about 500 bar (50 MPaa) or less, or about 300 bar (30 MPaa)or less, or about 100 bar (10 MPaa) or less. Under these conditions,entry of methane or other organic compounds can be reduced, minimized,or possibly eliminated. The minimized entry of methane or other organiccompounds into the adsorbent structure or membrane structure canfacilitate performing a separation with high selectivity.

As still another option, the separation can be performed at atemperature greater than about 270 K, or greater than about 325 K, orgreater than about 375 K, such as up to about 600 K or more.Additionally or alternately, the separation can be performed at apressure greater than about 100 bar (10 MPaa), or greater than about 300bar (30 MPaa), or greater than about 500 bar (50 MPaa), or greater thanabout 700 bar (70 MPaa), such as up to about 1500 bar (150 MPaa) ormore. Additionally or alternately, the separation can be performed atany combination of a temperature and pressure range cited in thisparagraph. Under these conditions, some methane or other organiccompound may be able to enter an adsorbent structure or membranestructure, but the separation can be performed with a selectivity asdescribed above.

Prophetic Example 4 Separation of O₂ from N₂

The following is a prophetic example. A commercially important type ofseparation is separation of O₂ from N₂. While air can be used as a feedfor some reactions, in many situations it can be desirable to have astream either enriched or depleted in oxygen relative to air. Inaddition to separating oxygen from nitrogen with a starting stream ofair, such separations can generally be performed on other streamscontaining both oxygen and nitrogen.

Nitrogen can be separated from oxygen using an adsorbent and/or membranethat includes zeolite ITQ-55. Adsorption can be performed using anyconvenient type of process, such as a swing adsorption process. Forseparation by adsorption, a stream that contains nitrogen and oxygen canbe exposed to an adsorbent structure. Oxygen can generally have asmaller kinetic diameter and/or higher affinity for ITQ-55, so it isbelieved that oxygen can preferentially enter the pore structure ofzeolite ITQ-55. The surface of the adsorbent structure can be composedof and/or include zeolite ITQ-55 in a manner so that fluids that enterthe adsorbent structure can enter by passing through pores of theITQ-55. Depending on the adsorbent structure, defects in the ITQ-55crystal structure and/or defects between crystals can allow some fluidsto enter the adsorbent structure without passing through the ITQ-55. Dueto such defects, less than 100% of the fluids entering the adsorbentstructure may pass through the ITQ-55 crystals, such as at least about90 vol %, or at least about 95%, or at least about 98%.

Similarly, for separation by permeation through a membrane, a streamthat contains nitrogen and oxygen can be exposed to a membranestructure. The surface of the membrane structure can be composed ofand/or include zeolite ITQ-55 in a manner so that fluids that enter themembrane structure can enter by passing through pores of the ITQ-55.Depending on the adsorbent structure, defects in the ITQ-55 crystalstructure and/or defects between crystals can allow some fluids to enterthe membrane structure without passing through the ITQ-55. Due to suchdefects, less than 100% of the fluids entering the membrane structuremay pass through the ITQ-55 crystals, such as at least about 90 vol %,or at least about 95%, or at least about 98%.

During a separation process, a fluid comprising oxygen and nitrogen canbe exposed to an adsorbent or membrane structure. Based on the relativekinetic diameters and/or the relative affinities of oxygen and nitrogenfor the ITQ-55, it is believed that the oxygen can preferentially enterthe adsorbent or membrane structure relative to nitrogen. This can allowfor selectivity for either oxygen or nitrogen (depending on the productstream that corresponds to a desired output), either for adsorption orfor separation via membrane, of at least about 5, or at least about 10,or at least about 20, or at least about 30.

Optionally, the adsorption separation or membrane can be performed at atemperature below 300 K, such as 275 K or less, or 250 K or less, or 225K or less, or 200 K or less. This can enhance the selectivity of theITQ-55 for performing the separation, as well as potentially increasingthe capacity of an adsorbent structure for holding nitrogen. Optionally,performing a separation at low temperature can also benefit fromallowing water to be condensed out of a fluid prior to the fluid beingexposed to the adsorbent or membrane structure. Optionally, a lowtemperature separation can be performed at any convenient pressure, suchas a pressure of 1000 bar (100 MPaa) or less. It is noted that at theseseparation conditions, the fluid being separated can optionallycorrespond to a liquid.

As another option, the separation can be performed at a temperature ofabout 270 K to about 375 K and at a pressure of about 700 bar (70 MPaa)or less, or about 500 bar (50 MPaa) or less, or about 300 bar (30 MPaa)or less, or about 100 bar (10 MPaa) or less. Under these conditions,entry of methane or other organic compounds can be reduced, minimized,or possibly eliminated. The minimized entry of methane or other organiccompounds into the adsorbent structure or membrane structure canfacilitate performing a separation with high selectivity.

As still another option, the separation can be performed at atemperature greater than about 270 K, or greater than about 325 K, orgreater than about 375 K, such as up to about 600 K or more.Additionally or alternately, the separation can be performed at apressure greater than about 100 bar (10 MPaa), or greater than about 300bar (30 MPaa), or greater than about 500 bar (50 MPaa), or greater thanabout 700 bar (70 MPaa), such as up to about 1500 bar (150 MPaa) ormore. Additionally or alternately, the separation can be performed atany combination of a temperature and pressure range cited in thisparagraph. Under these conditions, some methane or other organiccompound may be able to enter an adsorbent structure or membranestructure, but the separation can be performed with a selectivity asdescribed above.

Prophetic Example 5 Storage of Hydrocarbons and/or Small OrganicCompounds

The following is a prophetic example. Although a storage process forhydrocarbons can be initiated using a stream containing multiplecomponents, for clarity in description this prophetic example is basedon performing storage based on a single component stream.

In some aspects, storage of a hydrocarbon in an adsorbent structurecomprising ITQ-55 can be performed by initially adsorbing the ITQ-55 atan elevated temperature and/or pressure. Suitable compounds for storagecan include, but are not limited to, methane, ethane, ethylene,formaldehyde, methanol, dimethyl ether, and combinations thereof.

During an initial adsorption step, a fluid component can be adsorbedinto the adsorbent structure. The conditions during adsorption caninclude, for example, a) a temperature of at least about 325 K, or atleast about 375 K, or at least about 425 K, or at least about 475 K; b)a pressure of at least about 100 bar (10 MPaa), or at least about 300bar (30 MPaa), or at least about 500 bar (50 MPaa), or at least about700 bar (70 MPaa); or c) a combination thereof. Without being bound byany particular theory, the elevated temperature and/or pressure canallow for introduction of an elevated loading of an organic componentinto the adsorbent structure.

After loading of the adsorbent structure, the temperature and/orpressure can be reduced. In aspects where loading of the adsorbentstructure is performed at an elevated pressure, the pressure can bereduced to about 100 bar (10 MPaa) or less, or about 10 bar (1 MPaa) orless, or about 2 bar (0.2 MPaa) or less, or about 1 bar (0.1 MPaa) orless. In aspects where loading of the adsorbent structure is performedat an elevated temperature, the temperature can be reduced to about 325K or less, or about 300 K or less, or about 275 K or less, or about 250K or less, or about 225 K or less, or about 200 K or less. In aspectswhere both the temperature and pressure are elevated during loading, thetemperature can optionally be reduced first, and then the pressure canbe reduced. After reducing the temperature and/or pressure, somedesorption of the adsorbed component can occur. However, based on thereduced temperature and/or pressure conditions, a portion of thecomponent can remain kinetically trapped within the adsorbent structure.This can allow the adsorbent structure to retain an amount of the fluidcomponent within the adsorbent structure, even though the atmosphereoutside of the adsorbent may no longer contain the adsorbed component.The loading retained within the adsorbent can correspond to a percentageof the loading that was achieved during adsorption, such as at leastabout 10 wt % of the loading during adsorption, or at least about 20 wt%, or at least about 30 wt %, or at least about 40 wt %, or at leastabout 50 wt %, or at least about 60 wt %. The adsorbent structure canthen optionally be transported under the reduced temperature and/orpressure conditions.

After storage for a desired amount of time, the temperature can beincreased to allow the adsorbed component to exit from the adsorbentstructure. This can allow the adsorbed component, corresponding to afuel and/or potential reactant, to be stored and optionally transportedunder less severe conditions. In other words, the temperature and/orpressure required for storage of the adsorbed component in the adsorbentstructure can be reduced relative to the conditions required for storingthe adsorbed component in the absence of the adsorbent structure.

Additional Separation Embodiments Embodiment 1

A method for separating fluids, comprising: exposing an input fluidstream comprising a first fluid component and a second fluid componentto an adsorbent comprising zeolite ITQ-55 to form a rejection productfluid stream, a molar ratio of the first fluid component to the secondfluid component in the rejection product fluid stream being less than amolar ratio of the first fluid component to the second fluid componentin the input fluid stream; collecting the rejection product fluidstream; forming an adsorbed product fluid stream, a molar ratio of thefirst fluid component to the second fluid component in the adsorbedproduct stream being greater than the molar ratio of the first fluidcomponent to the second fluid component in the input fluid stream; andcollecting the adsorbed product stream, wherein the zeolite ITQ-55 has aframework of tetrahedral (T) atoms connected by bridging atoms, whereinthe tetrahedral atom is defined by connecting the nearest T atoms in themanner described in the following Table:

ITQ-55 tetrahedral atom interconnections T atom Connected to: T1 T6, T7,T55, T73 T2 T3, T5, T9, T56 T3 T2, T7, T21, T27 T4 T8, T9, T58, T73 T5T2, T8, T52, T59 T6 T1, T8, T53, T60 T7 T1, T3, T50, T61 T8 T4, T5, T6,T51 T9 T2, T4, T21, T63 T10 T15, T16, T64, T74 T11 T12, T14, T18, T65T12 T11, T16, T30, T36 T13 T17, T18, T67, T74 T14 T11, T17, T43, T68 T15T10, T17, T44, T69 T16 T10, T12, T41, T70 T17 T13, T14, T15, T42 T18T11, T13, T30, T72 T19 T24, T25, T37, T73 T20 T21, T23, T27, T38 T21 T3,T9, T20, T25 T22 T26, T27, T40, T73 T23 T20, T26, T41, T70 T24 T19, T26,T42, T71 T25 T19, T21, T43, T68 T26 T22, T23, T24, T69 T27 T3, T20, T22,T45 T28 T33, T34, T46, T74 T29 T30, T32, T36, T47 T30 T12, T18, T29, T34T31 T35, T36, T49, T74 T32 T29, T35, T50, T61 T33 T28, T35, T51, T62 T34T28, T30, T52, T59 T35 T31, T32, T33, T60 T36 T12, T29, T31, T54 T37T19, T42, T43, T75 T38 T20, T39, T41, T45 T39 T38, T43, T57, T63 T40T22, T44, T45, T75 T41 T16, T23, T38, T44 T42 T17, T24, T37, T44 T43T14, T25, T37, T39 T44 T15, T40, T41, T42 T45 T27, T38, T40, T57 T46T28, T51, T52, T76 T47 T29, T48, T50, T54 T48 T47, T52, T66, T72 T49T31, T53, T54, T76 T50 T7, T32, T47, T53 T51 T8, T33, T46, T53 T52 T5,T34, T46, T48 T53 T6, T49, T50, T51 T54 T36, T47, T49, T66 T55 T1, T60,T61, T75 T56 T2, T57, T59, T63 T57 T39, T45, T56, T61 T58 T4, T62, T63,T75 T59 T5, T34, T56, T62 T60 T6, T35, T55, T62 T61 T7, T32, T55, T57T62 T33, T58, T59, T60 T63 T9, T39, T56, T58 T64 T10, T69, T70, T76 T65T11, T66, T68, T72 T66 T48, T54, T65, T70 T67 T13, T71, T72, T76 T68T14, T25, T65, T71 T69 T15, T26, T64, T71 T70 T16, T23, T64, T66 T71T24, T67, T68, T69 T72 T18, T48, T65, T67 T73 T1, T4, T19, T22 T74 T10,T13, T28, T31 T75 T37, T40, T55, T58 T76 T46, T49, T64, T67.

Embodiment 2

A method for separating fluids, comprising: exposing an input fluidstream comprising a first fluid component and a second fluid componentto an adsorbent comprising zeolite ITQ-55 to form a rejection productfluid stream, a molar ratio of the first fluid component to the secondfluid component in the rejection product fluid stream being less than amolar ratio of the first fluid component to the second fluid componentin the input fluid stream; collecting the rejection product fluidstream; forming an adsorbed product fluid stream, a molar ratio of thefirst fluid component to the second fluid component in the adsorbedproduct stream being greater than the molar ratio of the first fluidcomponent to the second fluid component in the input fluid stream; andcollecting the adsorbed product stream, wherein the zeolite ITQ-55, assynthesized, has an X-ray diffraction pattern with, at least, the anglevalues 2θ (degrees) and relative intensities (I/I₀):

2θ (degrees) ± 0.5 Intensity (I/I₀) 5.8 w 7.7 w 8.9 w 9.3 mf 9.9 w 10.1w 13.2 m 13.4 w 14.7 w 15.1 m 15.4 w 15.5 w 17.4 m 17.7 m 19.9 m 20.6 m21.2 f 21.6 f 22.0 f 23.1 mf 24.4 m 27.0 m

-   -   where I₀ is the intensity from the most intense pick to which is        assigned a value of 100    -   w is a weak relative intensity between 0 and 20%,    -   m is an average relative intensity between 20 and 40%,    -   f is a strong relative intensity between 40 and 60%,        and mf is a very strong relative intensity between 60 and 100%.

Embodiment 3

The method of any of the above embodiments, wherein the zeolite ITQ-55has, in calcined state and in absence of defects in its crystallinematrix manifested by the presence of silanols, an empiric formulax(M_(1/n)XO₂):yYO₂ :gGeO₂:(1−g)SiO₂

-   -   in which    -   M is selected between H⁺, at least one inorganic cation of        charge +n, and a mixture of both,    -   X is at least one chemical element of oxidation state +3,    -   Y is at least one chemical element with oxidation state +4        different from Si,    -   x takes a value between 0 and 0.2, both included,    -   y takes a value between 0 and 0.1, both included,    -   g takes a value between 0 and 0.5, both included.

Embodiment 4

The method of Embodiment 3, wherein x takes a value of essentially zero,y takes a value of essentially zero, and g takes a value of essentiallyzero.

Embodiment 5

The method of Embodiment 3, wherein a) x takes a value of greater thanzero, b) y takes a value of greater than zero, c) g takes a value ofgreater than zero, or d) a combination thereof.

Embodiment 6

The method of any of the above embodiments, wherein forming an adsorbedproduct fluid stream comprises modifying at least one of the temperatureor the pressure of the adsorbent.

Embodiment 7

The method of any of the above embodiments, wherein forming an adsorbedproduct fluid stream comprises exposing a fluid stream comprising athird component to the adsorbent comprising zeolite ITQ-55, at least aportion of the third component being adsorbed by the adsorbentcomprising zeolite ITQ-55.

Embodiment 8

The method of any of the above embodiments, wherein exposing the inputfluid stream to an adsorbent comprises exposing the input fluid streamto an adsorbent in a swing adsorption vessel.

Embodiment 9

The method of Embodiment 8, wherein exposing the input fluid stream toan adsorbent comprises exposing the input fluid stream to the adsorbentunder pressure swing adsorption conditions, temperature swing adsorptionconditions, rapid cycle pressure swing adsorption conditions, or acombination thereof.

Embodiment 10

The method of any of the above embodiments, wherein the input fluidstream is exposed to the adsorbent at effective conditions forperforming a kinetic separation of the first component from the secondcomponent, at effective conditions for performing an equilibriumseparation of the first component from the second component, or acombination thereof.

Embodiment 11

The method of any of the above embodiments, wherein the adsorbent hasless than about 20% of open pore volume in pores having diametersgreater than about 20 Angstroms and less than about 1 micron.

Embodiment 12

A method for separating fluids, comprising: exposing an input fluidstream comprising a first fluid component and a second fluid componentto a membrane comprising particles of crystalline zeolite ITQ-55 to forma permeate product fluid stream and a rejection product fluid stream, amolar ratio of the first fluid component to the second fluid componentin the permeate product fluid stream being greater than a ratio of thefirst fluid component to the second fluid component in the input fluidstream, a molar ratio of the first fluid component to the second fluidcomponent in the rejection product fluid stream being less than a ratioof the first fluid component to the second fluid component in the inputfluid stream, wherein the tetrahedral atom is defined by connecting thenearest T atoms in the manner described in the following Table:

ITQ-55 tetrahedral atom interconnections T atom Connected to: T1 T6, T7,T55, T73 T2 T3, T5, T9, T56 T3 T2, T7, T21, T27 T4 T8, T9, T58, T73 T5T2, T8, T52, T59 T6 T1, T8, T53, T60 T7 T1, T3, T50, T61 T8 T4, T5, T6,T51 T9 T2, T4, T21, T63 T10 T15, T16, T64, T74 T11 T12, T14, T18, T65T12 T11, T16, T30, T36 T13 T17, T18, T67, T74 T14 T11, T17, T43, T68 T15T10, T17, T44, T69 T16 T10, T12, T41, T70 T17 T13, T14, T15, T42 T18T11, T13, T30, T72 T19 T24, T25, T37, T73 T20 T21, T23, T27, T38 T21 T3,T9, T20, T25 T22 T26, T27, T40, T73 T23 T20, T26, T41, T70 T24 T19, T26,T42, T71 T25 T19, T21, T43, T68 T26 T22, T23, T24, T69 T27 T3, T20, T22,T45 T28 T33, T34, T46, T74 T29 T30, T32, T36, T47 T30 T12, T18, T29, T34T31 T35, T36, T49, T74 T32 T29, T35, T50, T61 T33 T28, T35, T51, T62 T34T28, T30, T52, T59 T35 T31, T32, T33, T60 T36 T12, T29, T31, T54 T37T19, T42, T43, T75 T38 T20, T39, T41, T45 T39 T38, T43, T57, T63 T40T22, T44, T45, T75 T41 T16, T23, T38, T44 T42 T17, T24, T37, T44 T43T14, T25, T37, T39 T44 T15, T40, T41, T42 T45 T27, T38, T40, T57 T46T28, T51, T52, T76 T47 T29, T48, T50, T54 T48 T47, T52, T66, T72 T49T31, T53, T54, T76 T50 T7, T32, T47, T53 T51 T8, T33, T46, T53 T52 T5,T34, T46, T48 T53 T6, T49, T50, T51 T54 T36, T47, T49, T66 T55 T1, T60,T61, T75 T56 T2, T57, T59, T63 T57 T39, T45, T56, T61 T58 T4, T62, T63,T75 T59 T5, T34, T56, T62 T60 T6, T35, T55, T62 T61 T7, T32, T55, T57T62 T33, T58, T59, T60 T63 T9, T39, T56, T58 T64 T10, T69, T70, T76 T65T11, T66, T68, T72 T66 T48, T54, T65, T70 T67 T13, T71, T72, T76 T68T14, T25, T65, T71 T69 T15, T26, T64, T71 T70 T16, T23, T64, T66 T71T24, T67, T68, T69 T72 T18, T48, T65, T67 T73 T1, T4, T19, T22 T74 T10,T13, T28, T31 T75 T37, T40, T55, T58 T76 T46, T49, T64, T67.

Embodiment 13

A method for separating fluids, comprising: exposing an input fluidstream comprising a first fluid component and a second fluid componentto a membrane comprising particles of crystalline zeolite ITQ-55 to forma permeate product fluid stream and a rejection product fluid stream, amolar ratio of the first fluid component to the second fluid componentin the permeate product fluid stream being greater than a ratio of thefirst fluid component to the second fluid component in the input fluidstream, a molar ratio of the first fluid component to the second fluidcomponent in the rejection product fluid stream being less than a ratioof the first fluid component to the second fluid component in the inputfluid stream, wherein the zeolite ITQ-55, as synthesized, has an X-raydiffraction pattern with, at least, the angle values 2θ (degrees) andrelative intensities (I/I₀):

2θ (degrees) ± 0.5 Intensity (I/I₀) 5.8 w 7.7 w 8.9 w 9.3 mf 9.9 w 10.1w 13.2 m 13.4 w 14.7 w 15.1 m 15.4 w 15.5 w 17.4 m 17.7 m 19.9 m 20.6 m21.2 f 21.6 f 22.0 f 23.1 mf 24.4 m 27.0 m

-   -   where I₀ is the intensity from the most intense pick to which is        assigned a value of 100    -   w is a weak relative intensity between 0 and 20%,    -   m is an average relative intensity between 20 and 40%,    -   f is a strong relative intensity between 40 and 60%,    -   and mf is a very strong relative intensity between 60 and 100%.

Embodiment 14

The method of any of Embodiments 12 or 13, wherein the zeolite ITQ-55has, in calcined state and in absence of defects in its crystallinematrix manifested by the presence of silanols, an empiric formulax(M_(1/n)XO₂):yYO₂ :gGeO₂:(1−g)SiO₂

-   -   in which    -   M is selected between H⁺, at least one inorganic cation of        charge +n, and a mixture of both,    -   X is at least one chemical element of oxidation state +3,    -   Y is at least one chemical element with oxidation state +4        different from Si,    -   x takes a value between 0 and 0.2, both included,    -   y takes a value between 0 and 0.1, both included,    -   g takes a value between 0 and 0.5, both included.

Embodiment 15

The method of Embodiment 14, wherein x takes a value of essentiallyzero, y takes a value of essentially zero, and g takes a value ofessentially zero.

Embodiment 16

The method of Embodiment 14, wherein a) x takes a value of greater thanzero, b) y takes a value of greater than zero, c) g takes a value ofgreater than zero, or d) a combination thereof.

Embodiment 17

The method of any of Embodiments 12 to 16, wherein the membranecomprises particles of crystalline zeolite ITQ-55 having a mean particlesize of about 20 nm to about 1 micron.

Embodiment 18

The method of any of Embodiments 12 to 17, wherein the particles ofcrystalline zeolite ITQ-55 comprise a contiguous layer of particles.

Embodiment 19

The method of any of Embodiments 12 to 18, wherein the particles ofcrystalline zeolite ITQ-55 comprise a layer of particles of crystallinezeolite ITQ-55 on a support.

Embodiment 20

The method of Embodiment 19, wherein the support comprises glass, fusedquartz, silica, silicon, clay, metal, porous glass, sintered porousmetal, titania, cordierite, or a combination thereof.

Embodiment 21

The method of any of Embodiments 19 or 20, wherein the supported layerof particles of crystalline zeolite ITQ-55 comprises particles ofcrystalline zeolite ITQ-55 in a particulate matrix, a pore structurebeing defined by the interstices between the particles, between thecrystals, and between the particles and the crystals.

Embodiment 22

The method of any of Embodiments 12 to 21, wherein the membranecomprises at least one of a hybrid layer and a composite layer.

Embodiment 23

The method of any of Embodiments 12 to 22, further comprising exposing apermeate side of the membrane to a sweep stream.

Embodiment 24

The method of any of the above embodiments, wherein the second fluidcomponent is methane, ethane, methanol, dimethyl ether, an organiccompound containing 3 or more heavy atoms, or a combination thereof.

Embodiment 25

The method of Embodiment 24, wherein the first fluid component is CO,CO₂, H₂, H₂O, or a combination thereof.

Embodiment 26

The method of Embodiment 25, wherein the first fluid component is CO₂and the second fluid component is CH₄.

Embodiment 27

The method of Embodiment 26, wherein the input fluid stream comprisesnatural gas.

Embodiment 28

The method of Embodiment 24, wherein the first fluid component isethylene, acetylene, formaldehyde, or a combination thereof.

Embodiment 29

The method of Embodiment 24, wherein the first fluid component is H₂S,NH₃, or a combination thereof.

Embodiment 30

The method of Embodiment 24, wherein the first fluid component is SO₂,N₂O, NO, NO₂, a sulfur oxide, or a combination thereof, the input fluidoptionally comprising a flue gas.

Embodiment 31

The method of Embodiment 24, wherein the first fluid component is N₂,the input fluid stream optionally comprising a natural gas stream.

Embodiment 32

The method of Embodiment 31, wherein the input fluid stream is exposedto the adsorbent at a temperature of about 223 K to about 523 K,optionally at least about 270 K.

Embodiment 33

The method of Embodiment 24, wherein the first fluid component is anoble gas, a molecular halogen, a halogen hydride, or a combinationthereof

Embodiment 34

The method of any of the above embodiments, wherein the first fluidcomponent is methane, ethylene, ethane, methanol, dimethyl ether, or acombination thereof.

Embodiment 35

The method of any of the above embodiments, wherein the second fluidcomponent is nitrogen, the first fluid component being hydrogen, a noblegas, oxygen, a nitrogen oxide, CO₂, CO, a molecular halogen, a halogenhydride, or a combination thereof.

Embodiment 36

The method of Embodiment 35, wherein the first fluid component is CO₂.

Embodiment 37

The method of Embodiment 36, wherein the input fluid stream comprises aflue gas.

Embodiment 38

The method of Embodiment 35, wherein the first fluid component is O₂.

Embodiment 39

The method of Embodiment 26, wherein the input fluid stream comprisesair.

Embodiment 40

The method of Embodiment 35, wherein the molecular halogen or thehalogen halide comprise F, Cl, Br, or a combination thereof as thehalogen.

Embodiment 41

The method of any of the above embodiments, wherein the first fluidcomponent is CO₂ and the second fluid component comprises one or morehydrocarbons.

Embodiment 42

The method of Embodiment 29, wherein the one or more hydrocarbons aremethane, ethane, ethylene, or a combination thereof.

Embodiment 43

The method of any of the above embodiments, wherein the first fluidcomponent is ethylene and the second fluid component is ethane, methane,or a combination thereof.

Embodiment 44

The method of any of the above embodiments, wherein the first fluidcomponent is a nitrogen oxide and the second fluid component is a sulfuroxide.

Embodiment 45

The method of any of the above embodiments, wherein the first fluidcomponent is H₂ and the second fluid component is a nitrogen oxide, asulfur oxide, a hydrocarbon, a carbon oxide, or a combination thereof,the input fluid stream optionally comprising syngas.

Embodiment 46

The method of any of the above embodiments, wherein the first fluidcomponent is H₂ and the second fluid component is H₂S, NH₃, or acombination thereof.

Embodiment 47

The method of any of the above embodiments, wherein the first fluidcomponent is H₂O and the second fluid component is H₂.

Embodiment 48

The method of any of the above embodiments, wherein the first fluidcomponent is He, Ne, Ar, Kr, and the second fluid component is N₂, H₂O,CO, CO₂, a hydrocarbon, or a combination thereof.

Embodiment 49

The method of any of the above embodiments, wherein the first fluidcomponent is methanol, dimethyl ether, or a combination thereof.

Embodiment 50

The method of any of the above embodiments, wherein the second fluidcomponent is methanol, dimethyl ether, or a combination thereof.

Embodiment 51

The method of any of the above embodiments, wherein the first fluidcomponent is acetylene and the second fluid component is ethylene,methane, ethane, or a combination thereof.

Embodiment 52

The method of Embodiments 8 or 9, wherein the input fluid streamcomprises natural gas.

Embodiment 53

The method of Embodiment 52, wherein the input fluid stream is exposedto the adsorbent comprising zeolite ITQ-55 at a pressure of about 5 psia(about 0.03 MPa) to about 5000 psia (about 35 MPa), optionally at leastabout 250 psia (about 1.7 MPa), or at least about 500 psia (about 3.4MPa), or at least about 1000 psia (about 6.9 MPa).

Embodiment 54

The method of any of Embodiments 52 to 53, wherein the input fluidstream is exposed to the adsorbent at a temperature of about −18° C. toabout 399° C., or about 316° C. or less, or about 260° C. or less.

Embodiment 55

The method of any of Embodiments 52 to 54, wherein the first fluidcomponent is N₂, H₂O, CO₂, or a combination thereof.

Embodiment 56

The method of any of Embodiments 52 to 54, wherein the first fluidcomponent is at least one of N₂ and H₂O.

Embodiment 57

The method of any of Embodiments 52 to 54, wherein the first fluidcomponent is N₂.

Embodiment 58

The method of any of Embodiments 52 to 54, wherein the first fluidcomponent is H₂O.

Embodiment 59

The method of any of Embodiments 52 to 58, wherein the second fluidcomponent is CH₄, a hydrocarbon having a higher molecular weight thanCH₄, or a combination thereof.

Additional Storage Embodiments Embodiment 1

A method for adsorbing and storing fluids, comprising: exposing an inputfluid stream comprising a first fluid component to an adsorbentcomprising zeolite ITQ-55 at a first pressure and a first temperature;maintaining the adsorbent at a second pressure and a second temperaturefor a storage period of time; forming an adsorbed product fluid streamcomprising the first fluid component; and collecting the adsorbedproduct stream, wherein the tetrahedral atom is defined by connectingthe nearest T atoms in the manner described in the following Table:

ITQ-55 tetrahedral atom interconnections T atom Connected to: T1 T6, T7,T55, T73 T2 T3, T5, T9, T56 T3 T2, T7, T21, T27 T4 T8, T9, T58, T73 T5T2, T8, T52, T59 T6 T1, T8, T53, T60 T7 T1, T3, T50, T61 T8 T4, T5, T6,T51 T9 T2, T4, T21, T63 T10 T15, T16, T64, T74 T11 T12, T14, T18, T65T12 T11, T16, T30, T36 T13 T17, T18, T67, T74 T14 T11, T17, T43, T68 T15T10, T17, T44, T69 T16 T10, T12, T41, T70 T17 T13, T14, T15, T42 T18T11, T13, T30, T72 T19 T24, T25, T37, T73 T20 T21, T23, T27, T38 T21 T3,T9, T20, T25 T22 T26, T27, T40, T73 T23 T20, T26, T41, T70 T24 T19, T26,T42, T71 T25 T19, T21, T43, T68 T26 T22, T23, T24, T69 T27 T3, T20, T22,T45 T28 T33, T34, T46, T74 T29 T30, T32, T36, T47 T30 T12, T18, T29, T34T31 T35, T36, T49, T74 T32 T29, T35, T50, T61 T33 T28, T35, T51, T62 T34T28, T30, T52, T59 T35 T31, T32, T33, T60 T36 T12, T29, T31, T54 T37T19, T42, T43, T75 T38 T20, T39, T41, T45 T39 T38, T43, T57, T63 T40T22, T44, T45, T75 T41 T16, T23, T38, T44 T42 T17, T24, T37, T44 T43T14, T25, T37, T39 T44 T15, T40, T41, T42 T45 T27, T38, T40, T57 T46T28, T51, T52, T76 T47 T29, T48, T50, T54 T48 T47, T52, T66, T72 T49T31, T53, T54, T76 T50 T7, T32, T47, T53 T51 T8, T33, T46, T53 T52 T5,T34, T46, T48 T53 T6, T49, T50, T51 T54 T36, T47, T49, T66 T55 T1, T60,T61, T75 T56 T2, T57, T59, T63 T57 T39, T45, T56, T61 T58 T4, T62, T63,T75 T59 T5, T34, T56, T62 T60 T6, T35, T55, T62 T61 T7, T32, T55, T57T62 T33, T58, T59, T60 T63 T9, T39, T56, T58 T64 T10, T69, T70, T76 T65T11, T66, T68, T72 T66 T48, T54, T65, T70 T67 T13, T71, T72, T76 T68T14, T25, T65, T71 T69 T15, T26, T64, T71 T70 T16, T23, T64, T66 T71T24, T67, T68, T69 T72 T18, T48, T65, T67 T73 T1, T4, T19, T22 T74 T10,T13, T28, T31 T75 T37, T40, T55, T58 T76 T46, T49, T64, T67.

Embodiment 2

A method for adsorbing and storing fluids, comprising: exposing an inputfluid stream comprising a first fluid component to an adsorbentcomprising zeolite ITQ-55 at a first pressure and a first temperature;maintaining the adsorbent at a second pressure and a second temperaturefor a storage period of time; forming an adsorbed product fluid streamcomprising the first fluid component; and collecting the adsorbedproduct stream, wherein the zeolite ITQ-55, as synthesized, has an X-raydiffraction pattern with, at least, the angle values 2θ (degrees) andrelative intensities (I/I₀):

2θ (degrees) ± 0.5 Intensity (I/I₀) 5.8 w 7.7 w 8.9 w 9.3 mf 9.9 w 10.1w 13.2 m 13.4 w 14.7 w 15.1 m 15.4 w 15.5 w 17.4 m 17.7 m 19.9 m 20.6 m21.2 f 21.6 f 22.0 f 23.1 mf 24.4 m 27.0 m

-   -   where I₀ is the intensity from the most intense pick to which is        assigned a value of 100    -   w is a weak relative intensity between 0 and 20%,    -   m is an average relative intensity between 20 and 40%,    -   f is a strong relative intensity between 40 and 60%,    -   and mf is a very strong relative intensity between 60 and 100%.

Embodiment 3

The method of any of the above embodiments, wherein the zeolite ITQ-55has, in calcined state and in absence of defects in its crystallinematrix manifested by the presence of silanols, an empiric formulax(M_(1/n)XO₂):yYO₂ :gGeO₂:(1−g)SiO₂

-   -   in which    -   M is selected between H⁺, at least one inorganic cation of        charge +n, and a mixture of both,    -   X is at least one chemical element of oxidation state +3,    -   Y is at least one chemical element with oxidation state +4        different from Si,    -   x takes a value between 0 and 0.2, both included,    -   y takes a value between 0 and 0.1, both included,    -   g takes a value between 0 and 0.5, both included.

Embodiment 4

The method of Embodiment 3, wherein x takes a value of essentially zero,y takes a value of essentially zero, and g takes a value of essentiallyzero.

Embodiment 5

The method of Embodiment 3, wherein a) x takes a value of greater thanzero, b) y takes a value of greater than zero, c) g takes a value ofgreater than zero, or d) a combination thereof.

Embodiment 6

The method of any of the above embodiments, wherein exposing the inputfluid stream to an adsorbent comprises exposing the input fluid streamto an adsorbent in a swing adsorption vessel.

Embodiment 7

The method of any of the above embodiments, wherein the firsttemperature and the second temperature are the same, wherein the firstpressure and the second pressure are the same, or a combination thereof.

Embodiment 8

The method of any of the above embodiments, wherein forming an adsorbedproduct fluid stream comprises modifying the second temperature of theadsorbent.

Embodiment 9

The method of any of the above embodiments, wherein forming an adsorbedproduct fluid stream comprises exposing a fluid stream comprising athird component to the adsorbent comprising zeolite ITQ-55, at least aportion of the third component being adsorbed by the adsorbentcomprising zeolite ITQ-55.

Embodiment 10

The method of any of the above embodiments, wherein the adsorbent hasless than about 20% of open pore volume in pores having diametersgreater than about 20 Angstroms and less than about 1 micron.

Embodiment 11

The method of any of the above embodiments, wherein maintaining theadsorbent at a second pressure and a second temperature for a storageperiod of time comprises exposing the adsorbent to an environment havinga partial pressure of the first fluid component of about 0.1 MPaa orless.

Embodiment 12

The method of any of the above embodiments, wherein the input fluidstream further comprises a second component, a molar ratio of the firstcomponent to the second component in the adsorbed product stream isgreater than a molar ratio of the first component to the secondcomponent in the input fluid stream.

Embodiment 13

The method of Embodiment 12, wherein the second fluid component ismethane, ethane, methanol, dimethyl ether, an organic compoundcontaining 3 or more heavy atoms, or a combination thereof.

Embodiment 14

The method of Embodiment 12, wherein the first fluid component is H₂ andthe second fluid component is a nitrogen oxide, a sulfur oxide, ahydrocarbon, a carbon oxide, or a combination thereof, the input fluidstream optionally comprising syngas.

Embodiment 15

The method of Embodiment 12, wherein the first fluid component is H₂ andthe second fluid component is H₂S, NH₃, or a combination thereof.

Embodiment 16

The method of any of the above embodiments, wherein the first fluidcomponent is CO₂, H₂, or a combination thereof

Embodiment 17

The method of any of the above embodiments, wherein the first fluidcomponent is ethylene, acetylene, formaldehyde, or a combinationthereof.

Embodiment 18

The method of any of the above embodiments, wherein the first fluidcomponent is a noble gas, a molecular halogen, a halogen hydride, or acombination thereof.

Embodiment 19

The method of any of the above embodiments, wherein the first fluidcomponent is methane, ethylene, ethane, methanol, dimethyl ether, or acombination thereof.

Additional Catalysis Embodiments Embodiment 1

A method for converting organic compounds, comprising: exposing an inputfluid stream comprising an organic compound to a catalyst comprisingzeolite ITQ-55 under effective conversion conditions to form a convertedorganic compound, the conversion being catalyzed by the catalystcomprising zeolite ITQ-55, wherein the tetrahedral atom is defined byconnecting the nearest T atoms in the manner described in the followingTable:

ITQ-55 tetrahedral atom interconnections T atom Connected to: T1 T6, T7,T55, T73 T2 T3, T5, T9, T56 T3 T2, T7, T21, T27 T4 T8, T9, T58, T73 T5T2, T8, T52, T59 T6 T1, T8, T53, T60 T7 T1, T3, T50, T61 T8 T4, T5, T6,T51 T9 T2, T4, T21, T63 T10 T15, T16, T64, T74 T11 T12, T14, T18, T65T12 T11, T16, T30, T36 T13 T17, T18, T67, T74 T14 T11, T17, T43, T68 T15T10, T17, T44, T69 T16 T10, T12, T41, T70 T17 T13, T14, T15, T42 T18T11, T13, T30, T72 T19 T24, T25, T37, T73 T20 T21, T23, T27, T38 T21 T3,T9, T20, T25 T22 T26, T27, T40, T73 T23 T20, T26, T41, T70 T24 T19, T26,T42, T71 T25 T19, T21, T43, T68 T26 T22, T23, T24, T69 T27 T3, T20, T22,T45 T28 T33, T34, T46, T74 T29 T30, T32, T36, T47 T30 T12, T18, T29, T34T31 T35, T36, T49, T74 T32 T29, T35, T50, T61 T33 T28, T35, T51, T62 T34T28, T30, T52, T59 T35 T31, T32, T33, T60 T36 T12, T29, T31, T54 T37T19, T42, T43, T75 T38 T20, T39, T41, T45 T39 T38, T43, T57, T63 T40T22, T44, T45, T75 T41 T16, T23, T38, T44 T42 T17, T24, T37, T44 T43T14, T25, T37, T39 T44 T15, T40, T41, T42 T45 T27, T38, T40, T57 T46T28, T51, T52, T76 T47 T29, T48, T50, T54 T48 T47, T52, T66, T72 T49T31, T53, T54, T76 T50 T7, T32, T47, T53 T51 T8, T33, T46, T53 T52 T5,T34, T46, T48 T53 T6, T49, T50, T51 T54 T36, T47, T49, T66 T55 T1, T60,T61, T75 T56 T2, T57, T59, T63 T57 T39, T45, T56, T61 T58 T4, T62, T63,T75 T59 T5, T34, T56, T62 T60 T6, T35, T55, T62 T61 T7, T32, T55, T57T62 T33, T58, T59, T60 T63 T9, T39, T56, T58 T64 T10, T69, T70, T76 T65T11, T66, T68, T72 T66 T48, T54, T65, T70 T67 T13, T71, T72, T76 T68T14, T25, T65, T71 T69 T15, T26, T64, T71 T70 T16, T23, T64, T66 T71T24, T67, T68, T69 T72 T18, T48, T65, T67 T73 T1, T4, T19, T22 T74 T10,T13, T28, T31 T75 T37, T40, T55, T58 T76 T46, T49, T64, T67.

Embodiment 2

A method for converting organic compounds, comprising: exposing an inputfluid stream comprising an organic compound to a catalyst comprisingzeolite ITQ-55 under effective conversion conditions to form a convertedorganic compound, the conversion being catalyzed by the catalystcomprising zeolite ITQ-55, wherein the zeolite ITQ-55, as synthesized,has an X-ray diffraction pattern with, at least, the angle values 2θ(degrees) and relative intensities (I/I₀):

2θ (degrees) ± 0.5 Intensity (I/I₀) 5.8 w 7.7 w 8.9 w 9.3 mf 9.9 w 10.1w 13.2 m 13.4 w 14.7 w 15.1 m 15.4 w 15.5 w 17.4 m 17.7 m 19.9 m 20.6 m21.2 f 21.6 f 22.0 f 23.1 mf 24.4 m 27.0 m

-   -   where I₀ is the intensity from the most intense pick to which is        assigned a value of 100    -   w is a weak relative intensity between 0 and 20%,    -   m is an average relative intensity between 20 and 40%,    -   f is a strong relative intensity between 40 and 60%,    -   and mf is a very strong relative intensity between 60 and 100%.

Embodiment 3

The method of any of the above embodiments, wherein the zeolite ITQ-55has, in calcined state and in absence of defects in its crystallinematrix manifested by the presence of silanols, an empiric formulax(M_(1/n)XO₂):yYO₂ :gGeO₂:(1−g)SiO₂

-   -   in which    -   M is selected between H⁺, at least one inorganic cation of        charge +n, and a mixture of both,    -   X is at least one chemical element of oxidation state +3,    -   Y is at least one chemical element with oxidation state +4        different from Si,    -   x takes a value between 0 and 0.2, both included,    -   y takes a value between 0 and 0.1, both included,    -   g takes a value between 0 and 0.5, both included.

Embodiment 4

The method of Embodiment 3, wherein x takes a value of essentially zero,y takes a value of essentially zero, and g takes a value of essentiallyzero.

Embodiment 5

The method of Embodiment 3, wherein X is selected from Al, Ga, B, Fe,Cr, and combinations thereof, y takes the value 0, and g takes the value0.

Embodiment 6

The method of Embodiment 5, wherein the zeolite ITQ-55 comprises Si, O,and Al.

Embodiment 7

The method of Embodiment 6, wherein a ratio of Si to Al is from about10:1 to about 1000:1, optionally at least about 100:1.

Embodiment 8

The method of any of the above embodiments, wherein exposing the inputfluid stream to the catalyst comprising zeolite ITQ-55 comprisesexposing the input fluid stream to catalyst particles comprising zeoliteITQ-55.

Embodiment 9

The method of Embodiment 8, wherein the input fluid stream is exposed tothe catalyst particles comprising zeolite ITQ-55 in a fluidized bedreactor or a riser reactor.

Embodiment 10

The method of any of Embodiments 8 or 9, wherein the catalyst particlescomprising zeolite ITQ-55 further comprise a support, the supportcomprising silica, alumina, silica-alumina, zirconia, titania, or acombination thereof.

Embodiment 11

The method of any of Embodiments 8 to 10, wherein the catalyst particlescomprise a Group VI metal, a Group VIII metal, or a combination thereof.

Embodiment 12

The method of any of Embodiments 8 or 11, wherein the catalyst particlesfurther comprise a zeolite having a framework structure different fromzeolite ITQ-55.

Embodiment 13

The method of Embodiment 12, wherein the zeolite having a frameworkstructure different from zeolite ITQ-55 comprises a zeolite having aframework structure of MFI or FAU.

Embodiment 14

The method of any of the above embodiments, wherein the convertedorganic compound has a higher molecular weight than the organiccompound, or wherein the converted organic compound has a lowermolecular weight than the organic compound.

Embodiment 15

The method of any of the above embodiments, wherein the organic compoundcomprises methanol, methane, dimethyl ether, ethylene, acetylene, or acombination thereof.

Embodiment 16

The method of Embodiment 15, wherein the input feed further comprisesO₂, H₂O, or a combination thereof.

Embodiment 17

The method of any of Embodiments 15 or 16, wherein the converted organiccompound comprises ethylene.

Embodiment 18

The method of any of the above embodiments, wherein the organic compoundcomprises methanol and the converted organic compound comprises dimethylether.

Embodiment 19

The method of any of the above embodiments, wherein the organic compoundcomprises methanol and the converted organic compound comprises anolefin.

Embodiment 20

The method of any of the above embodiments, wherein the organic compoundcomprises methanol and the converted organic compound comprises a C₆-C₁₁aromatic.

Embodiment 21

The method of any of the above embodiments, wherein the organic compoundcomprises methane and the converted organic compound comprises analcohol, an olefin, a C₆-C₁₁ aromatic, or a combination thereof.

Embodiment 22

The method of any of the above embodiments, wherein the input feed isexposed to the catalyst comprising ITQ-55 in the presence of hydrogen.

Embodiment 23

The method of Embodiment 22, wherein organic compound comprises asulfur-containing compound and the converted organic compound comprisesa desulfurized organic compound.

Embodiment 24

The method of any of the above embodiments, wherein exposing the inputfluid to the catalyst comprising zeolite ITQ-55 comprises: exposing theinput fluid to the catalyst at conditions comprising a first temperatureand a first pressure; and modifying the conditions to a secondtemperature and a second pressure to expose at least a portion of theinput fluid to the catalyst at a second temperature and a secondpressure, a diffusion rate of the organic compound at the secondtemperature and the second pressure being about 50% or less of thediffusion rate at the first temperature and the first pressure, or about40% or less, or about 30% or less, or about 20% or less, or about 10% orless.

Embodiment 25

The method of Embodiment 24, wherein the second temperature is the sameas the first temperature.

Embodiment 26

The method of Embodiment 24, wherein the second temperature is lowerthan the first temperature.

Embodiment 27

The method of any of Embodiments 24 to 26, wherein the first pressure isat least about 100 bar (10 MPaa) and the second pressure is about 50 bar(5 MPaa) or less.

Additional Common Embodiments

The following Embodiments are suitable for combination with any of theAdditional Separation Embodiments, Additional Storage Embodiments, orAdditional Catalysis Embodiments described above.

Embodiment 1

The method of any of the above Additional Separation Embodiments,Additional Storage Embodiments, and/or Additional Catalysis Embodiments,wherein the zeolite ITQ-55, as synthesized, has an X-ray diffractionpattern with, at least, the angle values 2θ (degrees) and relativeintensities (I/I₀):

2θ (degrees) ± 0.5 Intensity (I/I₀) 5.8 w 7.7 w 8.9 w 9.3 mf 9.9 w 10.1w 13.2 m 13.4 w 14.7 w 15.1 m 15.4 w 15.5 w 17.4 m 17.7 m 19.9 m 20.6 m21.2 f 21.6 f 22.0 f 23.1 mf 24.4 m 27.0 m

-   -   where I₀ is the intensity from the most intense pick to which is        assigned a value of 100    -   w is a weak relative intensity between 0 and 20%,    -   m is an average relative intensity between 20 and 40%,    -   f is a strong relative intensity between 40 and 60%,    -   and mf is a very strong relative intensity between 60 and 100%.

Embodiment 2

The method of any of the above Additional Separation Embodiments,Additional Storage Embodiments, Additional Catalysis Embodiments, and/orAdditional Common Embodiment 1, wherein the ITQ-55 has a framework oftetrahedral (T) atoms connected by bridging atoms, wherein thetetrahedral atom is defined by connecting the nearest T atoms in themanner described in the following Table:

ITQ-55 tetrahedral atom interconnections T atom Connected to: T1 T6, T7,T55, T73 T2 T3, T5, T9, T56 T3 T2, T7, T21, T27 T4 T8, T9, T58, T73 T5T2, T8, T52, T59 T6 T1, T8, T53, T60 T7 T1, T3, T50, T61 T8 T4, T5, T6,T51 T9 T2, T4, T21, T63 T10 T15, T16, T64, T74 T11 T12, T14, T18, T65T12 T11, T16, T30, T36 T13 T17, T18, T67, T74 T14 T11, T17, T43, T68 T15T10, T17, T44, T69 T16 T10, T12, T41, T70 T17 T13, T14, T15, T42 T18T11, T13, T30, T72 T19 T24, T25, T37, T73 T20 T21, T23, T27, T38 T21 T3,T9, T20, T25 T22 T26, T27, T40, T73 T23 T20, T26, T41, T70 T24 T19, T26,T42, T71 T25 T19, T21, T43, T68 T26 T22, T23, T24, T69 T27 T3, T20, T22,T45 T28 T33, T34, T46, T74 T29 T30, T32, T36, T47 T30 T12, T18, T29, T34T31 T35, T36, T49, T74 T32 T29, T35, T50, T61 T33 T28, T35, T51, T62 T34T28, T30, T52, T59 T35 T31, T32, T33, T60 T36 T12, T29, T31, T54 T37T19, T42, T43, T75 T38 T20, T39, T41, T45 T39 T38, T43, T57, T63 T40T22, T44, T45, T75 T41 T16, T23, T38, T44 T42 T17, T24, T37, T44 T43T14, T25, T37, T39 T44 T15, T40, T41, T42 T45 T27, T38, T40, T57 T46T28, T51, T52, T76 T47 T29, T48, T50, T54 T48 T47, T52, T66, T72 T49T31, T53, T54, T76 T50 T7, T32, T47, T53 T51 T8, T33, T46, T53 T52 T5,T34, T46, T48 T53 T6, T49, T50, T51 T54 T36, T47, T49, T66 T55 T1, T60,T61, T75 T56 T2, T57, T59, T63 T57 T39, T45, T56, T61 T58 T4, T62, T63,T75 T59 T5, T34, T56, T62 T60 T6, T35, T55, T62 T61 T7, T32, T55, T57T62 T33, T58, T59, T60 T63 T9, T39, T56, T58 T64 T10, T69, T70, T76 T65T11, T66, T68, T72 T66 T48, T54, T65, T70 T67 T13, T71, T72, T76 T68T14, T25, T65, T71 T69 T15, T26, T64, T71 T70 T16, T23, T64, T66 T71T24, T67, T68, T69 T72 T18, T48, T65, T67 T73 T1, T4, T19, T22 T74 T10,T13, T28, T31 T75 T37, T40, T55, T58 T76 T46, T49, T64, T67.

When numerical lower limits and numerical upper limits are listedherein, ranges from any lower limit to any upper limit are contemplated.While the illustrative embodiments of the invention have been describedwith particularity, it will be understood that various othermodifications will be apparent to and can be readily made by thoseskilled in the art without departing from the spirit and scope of theinvention. Accordingly, it is not intended that the scope of the claimsappended hereto be limited to the examples and descriptions set forthherein but rather that the claims be construed as encompassing all thefeatures of patentable novelty which reside in the present invention,including all features which would be treated as equivalents thereof bythose skilled in the art to which the invention pertains.

The present invention has been described above with reference tonumerous embodiments and specific examples. Many variations will suggestthemselves to those skilled in this art in light of the above detaileddescription. All such obvious variations are within the full intendedscope of the appended claims.

What is claimed is:
 1. A method for converting oxygenates, comprising:exposing an input fluid stream comprising an oxygenate to a catalystcomprising zeolite ITQ-55 under conversion conditions to form aconverted compound comprising a dimethyl ether, olefins, aromatics, orany combination thereof, the conversion being catalyzed by the catalystcomprising zeolite ITQ-55, wherein the zeolite ITQ-55 has a framework oftetrahedral (T) atoms connected by bridging atoms, wherein thetetrahedral atom is defined by connecting the nearest T atoms in themanner described in the following Table: ITQ-55 tetrahedral atominterconnections T atom Connected to: T1 T6, T7, T55, T73 T2 T3, T5, T9,T56 T3 T2, T7, T21, T27 T4 T8, T9, T58, T73 T5 T2, T8, T52, T59 T6 T1,T8, T53, T60 T7 T1, T3, T50, T61 T8 T4, T5, T6, T51 T9 T2, T4, T21, T63T10 T15, T16, T64, T74 T11 T12, T14, T18, T65 T12 T11, T16, T30, T36 T13T17, T18, T67, T74 T14 T11, T17, T43, T68 T15 T10, T17, T44, T69 T16T10, T12, T41, T70 T17 T13, T14, T15, T42 T18 T11, T13, T30, T72 T19T24, T25, T37, T73 T20 T21, T23, T27, T38 T21 T3, T9, T20, T25 T22 T26,T27, T40, T73 T23 T20, T26, T41, T70 T24 T19, T26, T42, T71 T25 T19,T21, T43, T68 T26 T22, T23, T24, T69 T27 T3, T20, T22, T45 T28 T33, T34,T46, T74 T29 T30, T32, T36, T47 T30 T12, T18, T29, T34 T31 T35, T36,T49, T74 T32 T29, T35, T50, T61 T33 T28, T35, T51, T62 T34 T28, T30,T52, T59 T35 T31, T32, T33, T60 T36 T12, T29, T31, T54 T37 T19, T42,T43, T75 T38 T20, T39, T41, T45 T39 T38, T43, T57, T63 T40 T22, T44,T45, T75 T41 T16, T23, T38, T44 T42 T17, T24, T37, T44 T43 T14, T25,T37, T39 T44 T15, T40, T41, T42 T45 T27, T38, T40, T57 T46 T28, T51,T52, T76 T47 T29, T48, T50, T54 T48 T47, T52, T66, T72 T49 T31, T53,T54, T76 T50 T7, T32, T47, T53 T51 T8, T33, T46, T53 T52 T5, T34, T46,T48 T53 T6, T49, T50, T51 T54 T36, T47, T49, T66 T55 T1, T60, T61, T75T56 T2, T57, T59, T63 T57 T39, T45, T56, T61 T58 T4, T62, T63, T75 T59T5, T34, T56, T62 T60 T6, T35, T55, T62 T61 T7, T32, T55, T57 T62 T33,T58, T59, T60 T63 T9, T39, T56, T58 T64 T10, T69, T70, T76 T65 T11, T66,T68, T72 T66 T48, T54, T65, T70 T67 T13, T71, T72, T76 T68 T14, T25,T65, T71 T69 T15, T26, T64, T71 T70 T16, T23, T64, T66 T71 T24, T67,T68, T69 T72 T18, T48, T65, T67 T73 T1, T4, T19, T22 T74 T10, T13, T28,T31 T75 T37, T40, T55, T58 T76 T46, T49, T64, T67.

wherein the zeolite ITQ-55 has, in a calcined state and in an absence ofdefects in its crystalline matrix manifested by the presence ofsilanols, an empiric formulax(M_(1/n)XO₂):yYO₂ :gGeO₂:(1−g)SiO₂ in which M is selected from thegroup consisting of H⁺, at least one inorganic cation of charge +n, anda mixture of both, X is at least one chemical element of oxidation state+3, Y is at least one chemical element with oxidation state +4, whereinY is not Si, x is a value between 0 and 0.2, inclusive, y is a valuebetween 0 and 0.1, inclusive, g is a value between 0 and 0.5, inclusive.2. The method of claim 1, wherein x is zero, y is zero, and g is zero.3. The method of claim 1, wherein X is selected from the groupconsisting of Al, Ga, B, Fe, Cr, and combinations thereof, y is 0, and gis
 0. 4. The method of claim 3, wherein X is Al.
 5. The method of claim4, wherein a ratio of Si to Al is from about 10:1 to about 1000:1. 6.The method of claim 5, wherein the ratio of Si to Al is at least about100:1.
 7. The method of claim 1, wherein exposing the input fluid streamto the catalyst comprising zeolite ITQ-55 comprises exposing the inputfluid stream to catalyst particles comprising zeolite ITQ-55.
 8. Themethod of claim 7, wherein the input fluid stream is exposed to thecatalyst particles comprising zeolite ITQ-55 in a fluidized bed reactoror a riser reactor.
 9. The method of claim 7, wherein the catalystparticles comprising zeolite ITQ-55 further comprise a support, thesupport comprising silica, alumina, silica-alumina, zirconia, titania,or a combination thereof.
 10. The method of claim 7, wherein thecatalyst particles comprise a Group VI metal, a Group VIII metal, or acombination thereof.
 11. The method of claim 7, wherein the catalystparticles further comprise a zeolite having a framework structuredifferent from zeolite ITQ-55.
 12. The method of claim 11, wherein thezeolite having a framework structure different from zeolite ITQ-55comprises a zeolite having a framework structure of MFI or FAU.
 13. Themethod of claim 1, wherein the oxygenate comprises methanol, dimethylether, or a combination thereof.
 14. The method of claim 13, wherein theinput feed further comprises O₂, H₂O, or a combination thereof.
 15. Themethod of claim 1, wherein the oxygenate comprises methanol and theconverted compound comprises dimethyl ether.
 16. The method of claim 1,wherein the oxygenate comprises methanol and the converted compoundcomprises an olefin.
 17. The method of claim 1, wherein the oxygenatecomprises methanol and the converted compound comprises a C₆-C₁₁aromatic.
 18. The method of claim 1, wherein the input feed is exposedto the catalyst comprising ITQ-55 in the presence of hydrogen.
 19. Themethod of claim 1, wherein exposing the input fluid to the catalystcomprising zeolite ITQ-55 comprises: exposing the input fluid to thecatalyst at conditions comprising a first temperature and a firstpressure; and modifying the conditions to a second temperature and asecond pressure to expose at least a portion of the input fluid to thecatalyst at a second temperature and a second pressure, a diffusion rateof the organic compound at the second temperature and the secondpressure being about 50% or less of the diffusion rate at the firsttemperature and the first pressure.
 20. The method of claim 19, whereinthe second temperature is the same as the first temperature.
 21. Themethod of claim 19, wherein the second temperature is lower than thefirst temperature.
 22. The method of claim 19, wherein the firstpressure is at least-about 100 bar (10 MPaa) and the second pressure isabout 50 bar (5 MPaa) or less.
 23. A method for converting oxygenates,comprising: exposing an input fluid stream comprising an oxygenate to acatalyst comprising a zeolite under conversion conditions to form aconverted compound comprising a dimethyl ether, olefins, aromatics, orany combination thereof, the conversion being catalyzed by the catalystcomprising the zeolite, wherein the zeolite; has an X-ray diffractionpattern with, at least, the following angle values 2θ (degrees) andrelative intensities (I/I₀): 2θ (degrees) ± 0.5 Intensity (I/I₀) 5.8 w7.7 w 8.9 w 9.3 mf 9.9 w 10.1 w 13.2 m 13.4 w 14.7 w 15.1 m 15.4 w 15.5w 17.4 m 17.7 m 19.9 m 20.6 m 21.2 f 21.6 f 22.0 f 23.1 mf 24.4 m 27.0 m

where I₀ is the intensity from the most intense pick to which isassigned a value of 100 w is a weak relative intensity between 0 and20%, m is an average relative intensity between 20 and 40%, f is astrong relative intensity between 40 and 60%, and mf is a very strongrelative intensity between 60 and 100%; wherein the zeolite has, in acalcined state and in an absence of defects in its crystalline matrixmanifested by the presence of silanols, an empiric formulax(M_(1/n)XO₂):yYO₂ :gGeO₂:(1−g)SiO₂ in which M is selected from thegroup consisting of H⁺, at least one inorganic cation of charge +n, anda mixture of both, X is at least one chemical element of oxidation state+3, Y is at least one chemical element with oxidation state +4, whereinY is not Si, x is a value between 0 and 0.2, inclusive, y is a valuebetween 0 and 0.1, inclusive, g is a value between 0 and 0.5 inclusive.